mirror of https://github.com/jmthompson/ssc.git
62 lines
1.4 KiB
Plaintext
Executable File
62 lines
1.4 KiB
Plaintext
Executable File
Name Simple Serial Card;
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Partno SSC0001;
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Revision 01;
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Date 3/9/23;
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Designer Chris RYU;
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Company RyuCats;
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Location None;
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Assembly None;
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Device g22v10;
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/* Inputs */
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Pin 1 = reset;
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Pin 2 = CTS;
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Pin 3 = io_C800;
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Pin 4 = slot_select;
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Pin 5 = io_slot_access;
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Pin 6 = RW;
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Pin 7 = A11;
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Pin 8 = A10;
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Pin 9 = A9;
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Pin 10 = A8;
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Pin 11 = A3;
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/* Outputs */
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Pin 14 = rom_c800_enable;
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Pin 15 = rom_latch;
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Pin 16 = ls245_enable;
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Pin 17 = eprom_a8;
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Pin 18 = eprom_a9;
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Pin 19 = eprom_a10;
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Pin 20 = rom_enable;
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Pin 21 = PHI2;
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/* Latch (RS flip-flop) definition:
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Q = (Q & RESET) # !SET;
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*/
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PHI2 = !slot_select; /* per schematic */
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cf00_access = io_C800 # !(A8 & A9 & A10); /* CF00 access, pull low */
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/*
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if either reset or cf00 access is pulled low, then rom_latch = 1
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if io_slot_access is 0, then rom_latch = 0
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if io_slot_access is 1, then rom_latch = no change
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*/
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/* Q = ROM_LATCH RESET = io_slot_access SET = (reset & cf00_access) */
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rom_latch = (rom_latch & io_slot_access) # !(reset & cf00_access);
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rom_c800_enable = rom_latch # io_C800; /* enable if both pulled low */
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ls245_enable = ( io_slot_access & rom_c800_enable & slot_select); /* c800 ? */
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rom_enable = (io_slot_access & rom_c800_enable);
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eprom_a8 = A8 # !A11;
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eprom_a9 = A9 # !A11;
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eprom_a10 = A10 # !A11;
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