IBM PPC750FX - Page 92

Evaluation Board Manual
PPC750FX Evaluation Board Preliminary
CPLD Programming
Page 92 of 115
750FXebm_ch11.fm
June 10, 2003
del_rw_sreset[1].d = del_rw_sreset[0].q;
cpu0_sreset_n_ = (del_rw_sreset[0].q & del_rw_sreset[1].q) & (mpp0_sreset_n # !mpp_block_n);
-- above line: if mpp_block_n is 1 then allow mpp0_sreset# through.
cpu0_sreset_n = cpu0_sreset_n_;
cpu1_sreset_n_ = (del_rw_sreset[0].q & del_rw_sreset[1].q) & (mpp1_sreset_n # !mpp_block_n);
cpu1_sreset_n = cpu1_sreset_n_;
-- *** sreset logicend
-- *** treset logic start
del_rw_trst[1..0].clk = 25Mclk;
del_rw_trst[0].d = rw_trst;
del_rw_trst[1].d = del_rw_trst[0].q;
cpu_trst_n_ = !(initact & serial_eeprom)
& (del_rw_trst[0].q & del_rw_trst[1].q)
& sysreset_n & del_sysreset_n;
-- *** treset logicend
-- this reset signal is output to PCI bus (this is also the PCI reset input)
pci_reset_n = TRI(del_pgd, !target/host_n);
-- driven from 2.5V IO
cpu_trst_n = cpu_trst_n_;
-- If a fan fails (cpufan_ok_n = 1) turn on RED LED and shut down power supplies unless
-- "ignore_fans_n" =0 jumper is installed, then just turn on RED LED.
-- nofan_n = tri(gnd,fans_n);
nofan_n = tri(gnd,(cpufan_ok_n & ignore_fans_n)); -- good in ver 12_01
-- If ignore_fans_n jumper is installed (ignore_fans_n = 0) or
-- during sysreset_n = 0 or
-- cpufan_ok_n = 1 (bad or no fan) then turn on RED LED.
led_red_n = tri(gnd,(!ignore_fans_n # !sysreset_n # cpufan_ok_n));
END;