Datasheet
Preliminary
CPC945 Bridge and Memory Controller
Table 4-8. Processor Interface Power Management Signal Pins
I/O
Supply
Voltage
Signal
Levels
Signal Name
Signal Description
Signal Type
Processor sleep requests. To ensure correct operation, unused
inputs should be pulled down.
PI_QREQ[0:3]
PI_QACK[0:3]
Input
1.3 V - 1.5 V
1.3 V - 1.5 V
VDD2
VDD2
These signals provide the CPC945 acknowledgment to processor
sleep requests.
Output
Suspend request. This active-low signal is sent from the power
management unit (under software control) to the CPC945 to
request that the device stop all activity and enter the suspend
(sleep) state.
SUSPENDREQ_L
SUSPENDACK_L
Input
2.5 V
2.5 V
VDD5
VDD5
Suspend acknowledgment. The CPC945 asserts this active-low
signal back to the power management unit to indicate the suspen-
sion request has completed.
Output
Table 4-9. System Support Signal Pins
I/O
Signal
Type
Signal
Levels
Signal Name
Signal Description
Supply Notes
Voltage
The interrupt outputs from the CPC945 to the PowerPC 970xx
processors
IRQ[0:3]
Output
Input
1.3 V - 1.5 V VDD2
1
NORTH_BRIDGE_
RESET_L
Power on reset input to CPC945
2.5 V
VDD5
Note:
1. Recommended pull-up resistor = 1.0 kΩ.
2
Table 4-10. I C Signal Pins
I/O
Signal
Type
Signal
Levels
Signal Name
Signal Description
Supply Notes
Voltage
I2C slave only data bus. Used by the power management unit to
set up the processor interface and the debug facilities. It is also a
portal for diagnostic reads and writes to any system address.
PI_ISCA
I/O
2.5 V
VDD5
1
PI_ISCL
Strobe signal for PI_ISCA
I/O
I/O
I/O
2.5 V
2.5 V
2.5 V
VDD5
VDD5
VDD5
1
1
1
SYS_ISCA0
SYS_ISCL0
I2C master bus 0. Used to configure the system SDRAM.
Strobe signal for SYS_ISCA0
I2C master bus 1. This can also be used to configure the system
SDRAM.
SYS_ISCA1
SYS_ISCL1
I/O
I/O
2.5 V
2.5 V
VDD5
VDD5
1
1
Strobe signal for SYS_ISCA1
Note:
1. Recommended pull-up resistor = 2.05 kΩ.
A15-6009-03
December 18, 2007 - IBM Confidential
Dimensions and Pin Information
Page 41 of 69
IBM [ IBM ]
