IBM PPC750FX User Manual

Evaluation Board Manual
Preliminary PPC750FX Evaluation Board
750FXebm_ch11.fm
June 10, 2003
CPLD Programming
Page 81 of 115
FLASH/SRAM/BIG : NODE; -- boot from SRAM
BIG/SRAM/FLASH : NODE; -- boot BIG, then SRAM, flash on CS0
BIG/FLASH/SRAM : NODE; -- boot BIG, then flash, SRAM on CS0
halfclk : NODE;
sram_cs_n : NODE; -- node is low when either sram_cs is active low
WriteNVRAM_n : NODE; -- latched low write_n
-- | Lboot / LCS0
-- flash_n/sram_sel | bootsmall_n | above boot, boot / upper, lower
-- ============= |==========|=========================================
-- 0 | 0 | SRAM, small flash / big flash
-- 0 | 1 | - big flash - / SRAM, small flash
-- 1 | 0 | small flash, SRAM / big flash
-- 1 | 1 | - big flash - / small flash, SRAM
del_nvramcs : lpm_ff WITH (
LPM_WIDTH = 12,enable,aset,
LPM_FFTYPE = "DFF"
);
del_uart : lpm_ff WITH (
LPM_WIDTH = 10,enable,aset,
LPM_FFTYPE = "DFF"
);
halfclk_ : lpm_ff WITH (
LPM_WIDTH = 1,
LPM_FFTYPE = "DFF"
);
BEGIN
-- basic chip selects
!fpga_cs_n = !lcs_n[1] & !CSTiming_n; -- lcs1_n chip select
-- divide down 133Mhz clock to make 66MHz clock
halfclk_.enable = !nvram_burst_cs_n;
halfclk_.aset = nvram_burst_cs_n;
halfclk_.clock = sysclk;
halfclk_.data[0] = !halfclk_.q[0];
halfclk = halfclk_.q[0 ];
-- delay nvram_burst_cs_n for nine 66MHz clocks
del_nvramcs.enable = !nvram_burst_cs_n;
del_nvramcs.aset = nvram_burst_cs_n;
del_nvramcs.clock = halfclk;
del_nvramcs.data[0] = gnd;
del_nvramcs.data[1] = del_nvramcs.q[0];
del_nvramcs.data[2] = del_nvramcs.q[1];

IBM PPC750FX Specifications

General

Brand	IBM
Model	PPC750FX
Category	Motherboard
Language	English