Freescale Semiconductor, I

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1 Application Note Rev., 5/23 DC Motor 2 outputs version XOR version PU Function Set (DCm2Xor) By Milan Brejl, Ph.D. Functional Overview SW1_1 SW1_2 SW3_1 SW3_2 he DC Motor 2 outputs version XOR version (DCm2Xor) PU function is a version of the DC Motor 2 output version (DCm2) function that uses two PU channels to generate one PWM output channel. he PU channel outputs are connected to an XOR gate whos output is the required PWM signal. See Figure 1. An advantage of this solution is that the full range (% to 1%) of PWM duty-cycle ratios is available. here is no MPW (minimum pulse width) parameter to limit the edge duty-cycle ratios in this version, as opposed to the DCm2. A disadvantage is that the number of assigned PU channels is doubled. XOR XOR SW1 SW3 motor voltage PWM period center-time Figure 1. Functionality of XOR version illustation 5% PWM PWM period center-time he DCm2Xor PU functions, unlike the DCmXor, generates only the top channel signal of each PWM pair. he bottom channel signal can be derived from the top channel signal by external hardware. he function set consists of 5 PU functions: For More Information On his Product, Motorola, Inc., 23

2 DC Motor 2 outputs version XOR version C channels (DCm2Xor_C) DC Motor 2 outputs version XOR version channels (DCm2Xor_) Synchronization Signal for DC Motor 2 outputs version XOR version (DCm2Xor_sync) Resolver Reference Signal for DC Motor 2 outputs version XOR version (DCm2Xor_res) Fault Input for DC Motor 2 outputs version XOR version (DCm2Xor_fault) Function Set Configuration he DCm2Xor PU function set drives a DC Motor, independently of the CPU. he CPU is only required to set a duty-cycle (dc) parameter in the range ( 1,1), which determines both the speed and the direction. he function generates unipolar-switched center-aligned PWM signals. he DCm2Xor_C and DCm2Xor_ PU functions work together to generate 2 pairs of XOR gate inputs. he XOR gate outputs then produce a 2-channel 2- phase center-aligned PWM signal. he Synchronization Signal for the DCm2Xor function can be used to generate one or more adjustable signals for a wide range of uses. hese signals are synchronized to the PWM, and track changes in the PWM period. he Resolver Reference Signal for the DCm2Xor function can be used to generate one or more 5% duty-cycle adjustable signals that are also synchronized to the PWM.he Fault Input for the DCm2Xor function is a PU input function that sets all PWM outputs low when the input signal goes low. None of the PU functions in the DC Motor 2 outputs version XOR version PU function set can be used separately. he DCm2Xor_C and DCm2Xor_ functions have to be used together. he DCm2Xor_C runs on pins SW1_1 and SW3_1 see Figure 1. he DCm2Xor_ runs on the other pins. One or more channels running Synchronization Signal for DCm2Xor as well as Resolver Reference Signals for DCm2Xor functions can be added. hey can run with different settings on each channel. he function Fault Input for DCm2Xor can also be added. It is recommended to use it on channel 15, and to set the hardware option that disables all PU output pins when the channel 15 input signal is low (DPU bit = 1). his ensures that the hardware reacts quickly to a pin fault state. Note that it is not only the PWM channels, but all PU output channels, including the synchronization signals, that are disabled in this configuration. able 1 shows the configuration options and restrictions. 2 DC Motor 2 outputs version XOR version PU Function Set (DCm2Xor) For More Information On his Product,

3 Function Set Configuration able 1. DCm2Xor PU function set configuration options and restrictions PU function Optional/ Mandatory How many channels Assignable channels DCm2Xor_C mandatory 2 any 2 channels DCm2Xor_ mandatory 2 any 2 channels DCm2Xor_sync optional 1 or more any channels DCm2Xor_res optional 1 or more any channels DCm2Xor_fault optional 1 any, recommended is 15 and DPU bit set able 2 shows an example of configuration. able 2. Example of configuration Channel PU function Priority DCm2Xor_C high 1 DCm2Xor_ high 2 DCm2Xor_C high 3 DCm2Xor_ high 1 DCm2Xor_sync low 11 DCm2Xor_res low 15 DCm2Xor_fault high able 3 shows the PU function code sizes. PU function DCm2Xor_C DCm2Xor_ DCm2Xor_sync DCm2Xor_res DCm2Xor_fault able 3. PU function code sizes Code size 78 µ instructions + 8 entries = 68 long words 3 µ instructions + 8 entries = 11 long words 26 µ instructions + 8 entries = 34 long words 38 µ instructions + 8 entries = 46 long words 9 µ instructions + 8 entries = 17 long words Configuration Order he CPU configures the PU as follows. 1. Disables the channels by clearing the two channel priority bits on each channel used (not necessary after reset). 2. Selects the channel functions on all used channels by writing the function numbers to the channel function select bits. DC Motor 2 outputs version XOR version PU Function Set (DCm2Xor) 3 For More Information On his Product,

4 NOE: Detailed Function Description DC Motor 2 outputs version XOR version C channels (DCm2Xor_C) and DC Motor 2 outputs version XOR version channels (DCm2Xor_) 3. Initializes function parameters. he parameters and sync_presc_addr must be set before initialization. If a DCm2Xor_sync channel or a DCm2Xor_res channel is used, then its parameters must also be set before initialization. 4. Issues an HSR (Host Service Request) type %1 to one of the DCm2Xor_C channels to initialize all DCm2Xor_C and DCm2Xor_ channels. Issues an HSR type %1 to the DCm2Xor_sync channels, DCm2Xor_res channels and DCm2Xor_fault channel, if used. 5. Enables servicing by assigning high, middle or low priority to the channel priority bits. All DCm2Xor_C and DCm2Xor_ channels must be assigned the same priority to ensure correct operation. he CPU must ensure that the DCm2Xor_sync or DCm2Xor_res function is initialized after the initialization of DCm2Xor: assign a priority to the DCm2Xor_C and DCm2Xor_ channels to enable their initialization if a Synchronization Signal or a Resolver Reference Signal channel is used, wait until the HSR bits are cleared to indicate that initialization of the DCm2Xor_C and DCm2Xor_ channels has completed and assign a priority to the DCm2Xor_sync or DCm2Xor_res channel to enable its initialization A CPU routine that configures the PU can be generated automatically using the MPC5_Quick_Start Graphical Configuration ool. he DCm2Xor_C and DCm2Xor_ PU functions work together to generate 2 pairs of XOR gate inputs. he XOR gate outputs then produce a 2-channel 2- phase center-aligned PWM signal. Unlike the DCmXor, the generated signals are not top-bottom complementary pairs with dead-times but only top-like signals without dead-times. In order to charge the bootstrap transistors, the PWM signals start to run 1.6ms after their initialization (at 2MHz CR1 clock). he functions generate signals corresponding to a value in duty-cycle ratio dc until the first dc value is processed, or for at least for one PWM period. he CPU controls the PWM output by setting the PU parameters. he dutycycle ratio dc and PWM period can be adjusted during run time. he dutycycle ratio dc can gain a value in the range ( 1, 1). he sign controls the motion system direction, while the absolute value controls the amplitude of the applied voltage. he following figures show the input dc value and corresponding XOR gate outputs: 4 DC Motor 2 outputs version XOR version PU Function Set (DCm2Xor) For More Information On his Product,

5 Detailed Function Description dc = -.5 PWM period center-time dc = PWM period center-time dc =.5 PWM period center-time SW1 SW3 motor voltage Host Interface Figure 2. Unipolar switching he following equations describe how the PWM signal transition times SW1_1, SW1_2, SW3_1 and SW3_2 are calculated: dc = dc + dc X = 4 dc Y = 4 SW1_1 SW3_1 = center _ time X = center _ time Y Written By CPU Written By PU SW1_2 = center _ time + X SW3_2 = center _ time + Y Written by both CPU and PU Not Used 3 2 Name able 4. DCm2Xor_C Control Bits Channel Function Select Options DCm2Xor_C function number (Assigned during assembly the DPRAM code from library PU functions) DC Motor 2 outputs version XOR version PU Function Set (DCm2Xor) 5 For More Information On his Product,

6 3 2 Name Channel Priority Host Service Bits (HSR) Host Sequence Bits (HSQ) Channel Interrupt Enable Channel Interrupt Status Name able 4. DCm2Xor_C Control Bits Options Channel Disabled 1 Low Priority 1 Middle Priority 11 High Priority No Host Service Request 1 Not used 1 Initialization 11 Stop xx Not used x Not used x Not used able 5. DCm2Xor_ Control Bits Channel Function Select Channel Priority Host Service Bits (HSR) Host Sequence Bits (HSQ) Options DCm2Xor_ function number (Assigned during assembly the DPRAM code from library PU functions) Channel Disabled 1 Low Priority 1 Middle Priority 11 High Priority No Host Service Request 1 Not used 1 Not used 11 Not used xx Not used Channel Interrupt Enable x Not used Channel Interrupt Status x Not used 6 DC Motor 2 outputs version XOR version PU Function Set (DCm2Xor) For More Information On his Product,

7 Detailed Function Description able 6. DCm2Xor_C and DCm2Xor_ Parameter RAM Channel Parameter XY_X 1 SW13_2_ch_SW1 2 3 other_ch_sw1 4 dc fault_pinstate time_sw1_2 1 _copy CPU XY_Y 1 SW13_2_ch_SW3 2 3 other_ch_sw3 4 5 sync_presc_addr 6 7 time_sw3_ SW1_1 SW1_2 SW3_1 SW3_2 dc able 7. DCm2Xor_C and DCm2Xor_ parameter description Parameter Format Description Parameters written by CPU 16-bit fractional duty-cycle ratio in the range < 1,1) 16-bit unsigned integer PWM period in number of CR1 PU cycles DC Motor 2 outputs version XOR version PU Function Set (DCm2Xor) 7 For More Information On his Product,

8 Performance able 7. DCm2Xor_C and DCm2Xor_ parameter description Parameter Format Description CPU14 16-bit unsigned integer ime of 14 IMB clocks in CR1 clocks. sync_presc_addr 8-bit unsigned integer address of synchronization channel prescaler parameter: $X4, where X is synchronization channel number. $ if no synchronization channel is used. Parameters written by PU fault_pinstate or 1 If fault channel is used, state of fault pin:... low 1... high Other parameters are just for PU function inner use. able 8. DCm2Xor_ State Statistics State Max IMB Clock Cycles RAM Accesses by PU S 2 1 SF 2 able 9. DCm2Xor_C State Statistics State Max IMB Clock Cycles RAM Accesses by PU INI 5 1 SOP 52 1 C C2 1 4 Execution times do not include the time slot transition time (S = 1 or 14 IMB clocks) 8 DC Motor 2 outputs version XOR version PU Function Set (DCm2Xor) For More Information On his Product,

9 Detailed Function Description dc > % center-time dc < % center-time SW1_1 C1 C2 C2 SW1_2 SF S SF S SW3_1 C2 C1 C2 SW3_2 SF S SF S flag = 1 link Figure 3. DCm2Xor_C and DCm2Xor_ timing SF S SF S S SF S flag = 1 link Figure 4. DCm2Xor_ state diagram and 3 cases of timing NOE: he timing of the link determines which case accurs. DC Motor 2 outputs version XOR version PU Function Set (DCm2Xor) 9 For More Information On his Product,

10 INI C1 SOP HSR = 1 C2 HSR = 11 Synchronization signal for DC Motor 2 outputs version XOR version (DCm2Xor_sync) Figure 5. DCm2Xor_C state diagram he DCm2Xor_sync PU function uses information obtained from DCm2Xor_C and DCm2Xor_ functions, the actual PWM center times and the PWM periods. his allows a signal to be generated, that tracks the changes in the PWM period and is always synchronized with the PWM. he synchronization signal is a positive pulse generated repeatedly after the prescaler or presc_copy PWM periods (see next paragraph). he low to high transition of the pulse can be adjusted by a parameter, either negative or positive, to go before or after the PWM period center time of a number of CR1 PU cycles. he pulse width pw is another synchronization signal parameter. move > prescaler = 1 move < prescaler = 2 move pw pw move Figure 6. Synchronization signal adjustment examples 1 DC Motor 2 outputs version XOR version PU Function Set (DCm2Xor) For More Information On his Product,

11 Detailed Function Description Synchronized Change of PWM Prescaler And Synchronization Signal Prescaler he DCm2Xor_sync PU function actually uses the presc_copy parameter instead of the prescaler parameter. he prescaler parameter holds the prescaler value that is copied to the presc_copy by the DCm2Xor_bottom function at the time of the PWM parameters reload. his ensures that new prescaler values for the PWM signals, as well as the synchronization signal, are applied at the same time. Write the synchronization signals prescaler parameter address to the sync_presc_addr parameter to enable this mechanism. Write to disable it, and remember to set the synchronization signal presc_copy parameter instead of the prescaler parameter in this case. Host Interface Written By CPU Written By PU Written by both CPU and PU Not Used 3 2 able 1. DCm2Xor_sync Control Bits Name Channel Function Select Channel Priority Host Service Bits (HSR) Host Sequence Bits (HSQ) Channel Interrupt Enable Channel Interrupt Status Options DCm2Xor_sync function number (Assigned during assembly the DPRAM code from library PU functions) Channel Disabled 1 Low Priority 1 Middle Priority 11 High Priority No Host Service Request 1 Not used 1 Initialization 11 Not used xx Not used Channel Interrupt Disabled 1 Channel Interrupt Enabled Interrupt Not Asserted 1 Interrupt Asserted PU function DCm2Xor_sync generates an interrupt after each low to high transition. DC Motor 2 outputs version XOR version PU Function Set (DCm2Xor) 11 For More Information On his Product,

12 Performance able 11. DCm2Xor_sync Parameter RAM Channel Parameter move 1 pw 2 prescaler 3 presc_copy 4 time 5 dec 6 _copy Synchronization channel 7 able 12. DCm2Xor_sync parameter description Parameter Format Description Parameters written by CPU move 16-bit signed integer he number of CR1 PU cycles to forego (negative) or come after (positive) the PWM period center time pw 16-bit unsigned integer Synchronization pulse width in number of CR1 PU cycles. prescaler 16-bit unsigned integer he number of PWM periods per synchronization pulse use in case of synchronized prescalers change presc_copy 16-bit unsigned integer he number of PWM periods per synchronization pulse use in case of asynchronized prescalers change Parameters written by PU Other parameters are just for PU function inner use. here is one limitation. he absolute value of parameter move has to be less then a quarter of the PWM period. move < 4 12 DC Motor 2 outputs version XOR version PU Function Set (DCm2Xor) For More Information On his Product,

13 Detailed Function Description able 13. DCm2Xor_sync State Statistics State Max IMB Clock Cycles RAM Accesses by PU INI 12 5 S S2 8 3 S NOE: Execution times do not include the time slot transition time (S = 1 or 14 IMB clocks) HSR = 1 INI S1 S2 S3 S1 S2 Figure 7. DCm2Xor_sync timing S1 S2 S3 Figure 8. DCm2Xor_sync state diagram Resolver Reference Signal for DC Motor 2 outputs version XOR version (DCm2Xor_res) he DCm2Xor_res PU function uses information read from the DCm2Xor_C and DCm2Xor_ functions, the actual PWM center times and the PWM periods. his allows a signal to be generated, which tracks the changes of the PWM period and is always synchronized with the PWM. he resolver reference signal is a 5% duty-cycle signal with a period equal to prescaler or DC Motor 2 outputs version XOR version PU Function Set (DCm2Xor) 13 For More Information On his Product,

14 synchronization channel presc_copy PWM periods (see next paragraph). he low to high transition of the pulse can be adjusted by a parameter, either negative or positive, to go before or after the PWM period center time of a number of CR1 PU cycles. move > prescaler = 1 move move < prescaler = 2 Synchronized Change of PWM Prescaler And Resolver Reference Signals Prescaler Host Interface move Figure 9. Resolver reference signal adjustment examples he DCm2Xor_res PU function can inherit the Synchronization Signal prescaler that is synchronously changed with PWM prescaler. Write the synchronization signals presc_copy parameter address to the presc_addr parameter to enable this mechanism. Write to disable it, and in this case set prescaler parameter to directly specify prescaler value. 3 2 Written By CPU Written By PU able 14. DCm2Xor_res Control Bits Name Channel Function Select Channel Priority Written by both CPU and PU Not Used Options DCm2Xor_res function number (Assigned during assembly the DPRAM code from library PU functions) Channel Disabled 1 Low Priority 1 Middle Priority 11 High Priority 14 DC Motor 2 outputs version XOR version PU Function Set (DCm2Xor) For More Information On his Product,

15 Detailed Function Description able 14. DCm2Xor_res Control Bits Name Host Service Bits (HSR) Host Sequence Bits (HSQ) Options No Host Service Request 1 Not used 1 Initialization 11 Not used xx Not used Channel Interrupt Enable x Not used Channel Interrupt Status x Not used able 15. DCm2Xor_res Parameter RAM Channel Parameter move 1 2 presc_addr 3 prescaler 4 time 5 dec 6 _copy 7 Resolver able 16. DCm2Xor_res parameter description Parameter Format Description Parameters written by CPU move 16-bit signed integer he number of CR1 PU cycles to forego (negative) or come after (positive) the PWM period center time presc_addr 16-bit unsigned integer $X6, where X is a number of Synchronization Signal channel, to inherit Sync. channel prescaler or $ to enable direct specification of prescaler value in prescaler parameter DC Motor 2 outputs version XOR version PU Function Set (DCm2Xor) 15 For More Information On his Product,

16 able 16. DCm2Xor_res parameter description Parameter Format Description prescaler 1, 2, 4, 6, 8, 1, 12, 14,... he number of PWM periods per synchronization pulse use when apresc_addr = Parameters written by PU Other parameters are just for PU function inner use. Performance here is one limitation. he absolute value of parameter move has to be less than a quarter of the PWM period. move < 4 NOE: S1 able 17. DCm2Xor_res State Statistics State Max IMB Clock Cycles RAM Accesses by PU INI 12 5 S S Execution times do not include the time slot transition time (S = 1 or 14 IMB clocks) S3 Figure 1. DCm2Xor_res timing S1 16 DC Motor 2 outputs version XOR version PU Function Set (DCm2Xor) For More Information On his Product,

17 Detailed Function Description HSR = 1 INI S1 S3 Fault Input for DC Motor 2 outputs version XOR version (DCm2Xor_fault) Host Interface Figure 11. DCm2Xor_res state diagram he DCm2Xor_fault is an input PU function that monitors the pin, and if a high to low transition occurs, immediately sets all PWM channels low and cancels all further transitions on them. he PWM channels, as well as the synchronization and resolver reference signal channels (if used), have to be initialized again to start them running. he function returns the actual pinstate as a value of (low) or 1 (high) in the parameter fault_pinstate. he parameter is placed on the SW1_1 channel to keep the fault channel parameter space free. 3 2 Written By CPU Written By PU able 18. DCm2Xor_fault Control Bits Name Channel Function Select Channel Priority Written by both CPU and PU Not Used Options DCm2Xor_fault function number (Assigned during assembly the DPRAM code from library PU functions) Channel Disabled 1 Low Priority 1 Middle Priority 11 High Priority DC Motor 2 outputs version XOR version PU Function Set (DCm2Xor) 17 For More Information On his Product,

18 able 18. DCm2Xor_fault Control Bits Name Host Service Bits (HSR) Host Sequence Bits (HSQ) Options No Host Service Request 1 Not used 1 Initialization 11 Not used xx Not used Channel Interrupt Enable Channel Interrupt Disabled 1 Channel Interrupt Enabled Channel Interrupt Status Interrupt Not Asserted 1 Interrupt Asserted PU function DCm2Xor_fault generates an interrupt when a high to low transition appears. able 19. DCm2Xor_fault Parameter RAM Channel Parameter Fault input able 2. DCm2Xor_fault parameter description Parameter Format Description Parameters written by PU fault_pinstate or 1 State of fault pin:... low 1... high 18 DC Motor 2 outputs version XOR version PU Function Set (DCm2Xor) For More Information On his Product,

19 Detailed Function Description Performance able 21. DCm2Xor_fault State Statistics State Max IMB Clock Cycles RAM Accesses by PU INI 8 2 FAUL 58 2 NO_FAUL 4 1 NOE: Execution times do not include the time slot transition time (S = 1 or 14 IMB clocks) FAUL NO_FAUL HSR = 1 INI Figure 12. DCm2Xor_fault timing FAUL NO_FAUL Figure 13. DCm2Xor_fault state diagram DC Motor 2 outputs version XOR version PU Function Set (DCm2Xor) 19 For More Information On his Product,

20 Rev. 5/23 For More Information On his Product,