OCPRF100 MP Server System Technical Product Specification

Revision 1.0

Table 8-4: P1 Functions

Bit

Name

I/O

Fixed†

Function

 

 

 

 

 

7

SDA

I/O

Y

I2C serial data signal for the IPMB.

 

 

 

 

 

6

SCL

I/O

Y

I2C serial clock signal for the IPMB.

5

Reserved

-

N

Reserved for future use.

 

 

 

 

 

4

SCSI _reset_L

O

N

Reset SCSI controller. If 0, places the 53C80S SCSI chip into

 

 

 

 

reset. If 1, the SCSI interface chip comes out of reset and oper-

 

 

 

 

ates normally.

 

 

 

 

 

3

SCSI_DRQ

I

N

SCSI DMA Request. Connected to the DRQ signal of the

 

 

 

 

53C80S SCSI chip. Allows the microcontroller to use the DMA

 

 

 

 

transfer capabilities of the SCSI interface chip, which results in

 

 

 

 

higher performance.

 

 

 

 

 

2

Reserved

-

N

Reserved for future use.

 

 

 

 

 

1

SDA_Local

I/O

N

Serial data for private I2C connection to temperature sensor.

0

SCL_Local

O

N

Serial clock for private I2C connection to temperature sensor.

Notes:† “Fixed” indicates whether the function/pin is defined by the microcontroller pinout (fixed) or is implementation-specific (not fixed).

8.6.2.3P2

P2 is the high-order address and data bus for external device access. It is not used for general I/ O purposes.

8.6.2.4P3

P3 provides four dedicated-function signals, and four implementation-specific control signals, as shown in Table 8-5: P3 Functions.

Table 8-5: P3 Functions

Bit

Name

I/O

Fixed†

Function

 

 

 

 

 

7

RD_L

O

Y

Read strobe. Indication from the microcontroller that the current

 

 

 

 

bus cycle is a read operation.

 

 

 

 

 

102