Philips Semiconductors
Product data
Glue chip 4
PCA9504A
PIN DESCRIPTION
PIN(S)
SYMBOL
FUNCTION
1
3I
VREF3IN
3.3 V input
2
P
V_5P0_STBY
V_3P3_STBY
5 V system standby power supply
3
P
3 V system standby power supply
4
3IU
GPO_FLUSH_CACHE / GP2_IN
A20M / GP1_INB
INIT / GP1_INA
FLUSH_OUT_CPU / GP1_OUT
INIT_OUT / GP2_OUT
CLK_IN
GPO from SIO / ICH2 / Buffer 2 input
A20M signal from ICH2 / NAND 1 input B
INIT signal from the ICH2 / Buffer 1 input A
5
REF
REF
5V OD
5V OD
3I
6
7
Open drain signal, goes to the CPU / NAND 1 output
Delayed INIT signal into the CPU / Buffer 2 output
Either 33MHz or 66MHz clock, based on SEL_33_66 pin
Strapping option for 33MHz or 66MHz CLK_IN
Ground
8
9
10
11, 29, 43
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
30
31
32
33
34
35
36
37
38
39
40
41
42
44
45
46
47
48
49
3IU
SEL_33_66
G
GND
3I
PCRIST
PCI reset signal
3O
PCRIST_OUT
AUD_EN
Copy of PCRIST, increased drive-strength
Audio enable input (GPO from ICH2 / SIO)
Audio reset output
3IU
3O
AUD_RST
5O
IDE_RSTDRV
3V_DDCSCL
5V_DDCSCL
3V_DDCSDA
5V_DDCSDA
CPU_PRESENT
SLP_S3
IDE reset output, 5 V push/pull
3IOD
5IOD
3IOD
5IOD
3IU
DDCSCL input/output 3.3 V side
DDCSCL input/output 5 V side
DDCSDA input/output 3.3 V side
DDCSDA input/output 5 V side
CPU present signal from the processor
Signal from ICH2 for transitioning to the S3 power state
Power supply turn-on signal
3I
5V OD
5V OD
5IU
PS_ON
HD_LED
Hard drive front panel LED output
IDE primary drive active input
PRIMARY_HD
SCSI
5IU
SCSI drive active input
5IU
SECONDARY_HD
BACKFEED_CUT
LATCHED_BACKFEED_CUT
FLUSH_OUT_FWH
PWRGD_PS
FPRST
IDE secondary drive active input
Signal used for STR circuitry
5V OD
5O
Signal used for STR circuitry
5V OD
5IU
Open drain signal, goes to the FWH
Power good signal from power supply
Reset signal from the front panel
3.3 V power good output
5IU
3O
PWRGD_3V
SCK_BJT_GATE
SLP_S5
5V OD
3I
Gate signal from the SCK BJT in suspend to RAM
Signal from the ICH2 for transitioning to the S5 power state
Power LED input, from SIO GPIO
Power LED input, from SIO GPIO
Power LED output
3IU
GRN_BLNK
3IU
YLW_BLNK
5V OD
5V OD
5ID
YLW_LED
GRN_LED
Power LED output
TEST_EN
Test enable, 100K internal pull-down to GND
Reset for the ICH2 resume well
3O
RSMRST
AO
REF5V
Highest system supply reference voltage
5V system primary supply input
5I
VREF5IN
3IU
MUTE_AUD
AUD_SHDN
REF5V_STBY
HSYNC_3V
Signal from SIO to mute audio on power up/down
Signal to audio amp to signal shutdown
Highest system standby voltage
HSYNCH input from chipset video
5O
AO
3I
3
2004 May 11