AHA Application Note. Serial I/O Interface to AHA4011/AHA4012

Size: px

Start display at page:

Download "AHA Application Note. Serial I/O Interface to AHA4011/AHA4012"

Jemima Wells
5 years ago
Views:

1 AHA Application Note Serial I/O Interface to AHA0/AHA0 ANRS0_077 Comtech EF Data Corporation Alturas Drive Moscow ID 88 tel: fax:

2 Table of Contents.0 Introduction Description About AHA ANRS0_077 Comtech EF Data Corporation i

3 Figures Figure : Timing, Serial Data In Figure : Timing, Serial Data Out Figure : I/O Schematic ii Comtech EF Data Corporation ANRS0_077

4 .0 INTRODUCTION This Application Note describes a suggested circuit solution for a Serial I/O interface to the AHA0 or AHA0 Reed-Solomon encoder/decoder chips. Included with this document are a schematic and a timing diagram for the I/O. An OrCad electronic copy of the schematic is available upon request from AHA Applications Engineering. This schematic represents an example of what is possible and has not been verified in actual hardware. AHA Applications Engineering is available to assist with a system implementation of this hardware..0 DESCRIPTION The schematic includes a serial input port and a serial output port, an AHA0 or AHA0 part and some control logic. The AHA0 or AHA0 is referred to as the RS device in this App Note. The two V8 GALs contain two state machine controllers for generation of the required signals needed for this design. The GALs and the shift registers may be integrated into an on-board FPGA. The input GAL, U, derives control signals, DSIN and RSTN for the RS device from the input signals, INITN, RESETN and S. The GAL counts and generates a DSIN once every 8 S strobes. RSTN is generated when the system issues a RESETN or when INITN is generated. The output GAL, U, generates DSON for the RS device and strobes for the shift register, U. The GAL monitors RDYON and generates a DSON once every 8 SOUT strobes. The following list describes the I/O signals on this schematic. A free running clock running at the serial data rate. Maximum frequency is 0 MHz. RDYIN A low active signal generated by the RS device indicating the chip is ready for data input. DATAINPUT The serial data line into the HC shift register. S The serial data clock. DATAINPUT should contain valid data on each rising edge of S. INITN When the system is ready to send initialization values to the RS device, this signal must be asserted for the duration of the values. This signal is OR'd with RESETN to produce RSTN to the RS device. RESETN This signal produces a Reset to the RS device. ERASE An input to the RS device. Please refer to the appropriate RS device product specification for proper use of this signal. DATAOUT Serial data output from the output shift register. SOUT Serial output clock. DATAOUT contains valid data on each rising edge of the SOUT signal. ANRS0_077 Comtech EF Data Corporation Page of

5 Figure : Timing, Serial Data In S DATAINPUT DI7 DI DI DI DI DI DI DI0 DI7 RDYIN Figure : Timing, Serial Data Out SOUT DATAOUT DO7 DO DO DO DO DO DO DO0 DO7 RDYON Page of Comtech EF Data Corporation ANRS0_077

6 Figure : I/O Schematic Free running clock same freq. as S DATAINPUT S ERASE RESETN INITN 8 U A B CLR 7HC QA QB QC QD QE QF QG QH U I0 I I I I I I I7 I8 I V8 F0 F F F F F F F7 DI0 DI DI DI DI DI DI DI7 7 8 U RDYIN DI0 DI DI DI DI DI DI DI7 DO0 DO DO DO DO DO DO DO7 DSIN ERASE DSON RSTN RDYON CRTN ERR AHA0 / AHA DO0 DO DO DO DO DO DO DO7 7 8 U I0 I I I I I I I7 I8 I V8 F0 F F F F F F F U SER A B C D E F G H QH INH SH / ~ CLR 7HC RDYIN Ready to input data DATAOUT SOUT Notes: ) U is a divide by 8 counter which generates the DSIN strobe to the AHA0 part. ) U is a State Machine controller which generates the DSON strobe to the AHA0 part and controls the output shift register. ANRS0_077 Comtech EF Data Corporation Page of

7 .0 ABOUT AHA The AHA Products Group (AHA) of Comtech EF Data Corporation develops and markets superior integrated circuits, boards, and intellectual property cores for improving the efficiency of communications systems everywhere. AHA has been setting the standard in Forward Error Correction and Lossless Data Compression for many years and provides flexible and cost effective solutions for today s growing bandwidth and reliability challenges. Comtech EF Data is a wholly owned subsidiary of Comtech Telecommunications Corporation (NASDAQ CMTL). For more information, visit: Page of Comtech EF Data Corporation ANRS0_077

AHA Application Note. enhanced Turbo Product Codes (etpcs)

AHA Application Note. enhanced Turbo Product Codes (etpcs) AHA Application Note enhanced Turbo Product Codes (etpcs) ANTPC12_0306 Comtech F ata Corporation 1126 Alturas rive Moscow I 83843 tel: 208.892.5600 fax: 208.892.5601 www.aha.com Table of Contents 1.0 Introduction................................................................1