Intel® IXP42X product line and IXC1100 control plane processors—General Purpose Input/
Output (GPIO)
Intel® IXP42X Product Line of Network Processors and IXC1100 Control Plane Processor
DM September 2006
392 Order Number: 252480-006US
12.4.2 GPIO Output Enable Register(GPOER)

Each pin’s output tristate buffer is controlled by programming this register. Each of the

16 bits in the register represents the control to the tristate buffer of the output pin.

12.4.3 GPIO Input Register(GPINR)

This is a read-only register. This register contains the level of the I/O pin, either a 1 or

a 0.

Register GPOUTR
Bits Name Description
31:16 (Reserved). Reads back 0.
15 DO15
1 = Output a 1 on output pin, depends on GPCLKR24, GPOER15
0 = Output a 0 on output pin, depends on GPCLKR24, GPOER15
Reset: 0
14 DO14
1 = Output a 1 on output pin, depends on GPCLKR8, GPOER14
0 = Output a 0 on output pin, depends on GPCLKR8, GPOER14
Reset: 0
13:9 DO13:DO9
1 = Output a 1 on output pin, depends on GPOER[13:9]
0 = Output a 0 on output pin, depends on GPOER[13:9]
Reset: 0
8:0 DO8:DO0
1 = Output a 1 on output pin GPOER[8:0]
0 = Output a 0 on output pin GPOER[8:0]
Reset: 0
Register Name: GPOER
Hex Offset Address: 0xC800 4004 Reset Hex Value: 0x00007FFF
Register
Description: I/O Output Enable register. Turns on output driver.
Access: Read/Write.
31 161514131211109876543210
(Reserved)
OE15
OE14
OE13
OE12
OE11
OE10
OE9
OE8
OE7
OE6
OE5
OE4
OE3
OE2
OE1
OE0
Register GPOER
Bits Name Description
31:16 (Reserved). Reads back 0.
15 OE15
1 = Output pin is tristated or input
0 = Output pin is driven
Reset: 0 (as clock is driven out on this pin during reset).
14:0 OE14:OE0
1 = Output pin is tristated or input
0 = Output pin is driven
Reset: 1