FIRST RESET SIGNAL ON COMPUTER CIRCUIT

FIRST RESET SIGNAL ON COMPUTER CIRCUIT

RSMRST#
When the Power,Bios,Ec are OK, the RSMRST# will go Hi. In the other word,this pin go Low only when the systemreset.If BIOSdata is error,RSMRST# won’t go HI.
When SIO(EC) get +V_RTC
thecrystal will work.
1. RTC have to be oscillating(32.768KHz).
2. RTCRST# have to be high.
3. RSMRST# have to be inactive (high).
4. PWRBTN# have a trigger.
5. LOW_BAT# have to be inactive (high).
If this 5 present, then EC will recieve SLP_S3# / SLP_S5 from ICH/PCH, in the old ICH or some deferent circuirity SLP_S3 and SLP_S5 will generate directly from ICH,or both EC and PCH having this signal also.
When All+V?S/+V? powers are ready, PWR_GOOD will tie to high to turn on CPU powers(+VCCP and +VCC_CORE).
SB/PCH Power good--->SB/PCH pwr_btn--->PCH RUN
SUSB# from PCH toSIO pull up the signal SLP_S3# The signal is used to shut power off /on through logic gate transistor or IC
SUSC# from PCH to SIO pull up the signal SLP_S5# The signal is used to shut power off /on through logic gate transistor or IC
ICH/SB,MCH & CPU Signal Checking
IMVP_PWRGD => CLK_ENABLE# => RESET_OUT#=> ICH_PWRGD => PLTRST# => PCI_RST=> H_PWRGOOD
CPU generate the first cycle to read the BIOS code
CPU bus DMI LPC SPI
CPU ===> GMCH===> ICH===>SIO ===> BIOS
CPU MASTER POWER
VR_ON Enable--->+VCCORE 08VS to 1,5VS
Memory +VTT and +V1.5VS (DDR3) is ok, the PGOOD VTT_PWRGD pull high to CPU first than ICH will tie H_PWRGD to high ,then NB will tie CPURST# to reset CPU.
Crystal clock Oscilator CLOCK SUMMARY
(1) 32.768KHz to SIO Required +V_RTC and to ICH(chipset) also Required +V_RTC
(2) 49.152MHz to (audio controller) Required +V3S
(3) 27MHz to Graphic chip (video controller )Required +V3S
(4) 14.318MHz to (clock Generator) Required +V3S
Make sure crystal is oscillating for EC(SIO),SB/ICH/PCH and VGA or it will no post
Clock Generator
Elementary required
1) Power : +V3S
(2) Crystal : 14.318MHz
(3) Control : PCISTOP# , CPUSTOP#_ is HI
When +VCC_CORE is ready, CLKEN#will go high to enable clock-Generator and turn all clock.
PCI_STOP# and CPU_STOP# must beat high otherwise some clocks will be turned off.
Clock out -->SIO(EC)-->PCH/SB-->NB-->CPU
LPC_Frame-->SB output signal is high
Note High signal can be identified by measuring 3.3V available

Link Ref : https://sscomputerbth.blogspot.co.id/p/first-reset-signal-on-computer-circuit.html