Difference between revisions of "General Purpose Input/Output"
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| + | General Purpose Input and Output is a simple method of communication. Currently the [[shell]] implements the led and gpiostat commands to use these ports. | ||
| + | |||
== Port Assignments == | == Port Assignments == | ||
{| border="1" | {| border="1" | ||
| Line 11: | Line 13: | ||
| GPIO 3 || Cisco LED Orange | | GPIO 3 || Cisco LED Orange | ||
|- | |- | ||
| − | | GPIO 4 || | + | | GPIO 4 || Cisco Button |
|- | |- | ||
| GPIO 5 || ''Unkown'' | | GPIO 5 || ''Unkown'' | ||
|- | |- | ||
| − | | GPIO 6 || | + | | GPIO 6 || Reset Button |
|- | |- | ||
| GPIO 7 || DMZ LED | | GPIO 7 || DMZ LED | ||
|} | |} | ||
| + | |||
| + | == Registers == | ||
| + | There are four control and status registers, each which is 2 bytes. | ||
| + | * Input (0xb8000060) - If a GPIO pin is set for output, its input bit is automatically set to 0. | ||
| + | * Output (0xb8000064) - If a GPIO pin is set for input, its output bit is automatically set to 0. | ||
| + | * Enable (0xb8000068) - Determines if a GPIO pin is used for input or output. A bit value of 0 is input and 1 is output. | ||
| + | * Control (0xb800006c) - Usage is currently unknown. | ||
== LEDs == | == LEDs == | ||
Research Notes: | Research Notes: | ||
| + | * An LED is enabled by setting its enable bit to 1. | ||
* When an LED is enabled, its input bit becomes 0. | * When an LED is enabled, its input bit becomes 0. | ||
* Once an LED is enabled, if its output bit is 0, the LED is on and if its output bit is 1, the LED is off. | * Once an LED is enabled, if its output bit is 0, the LED is on and if its output bit is 1, the LED is off. | ||
Latest revision as of 23:03, 18 July 2007
General Purpose Input and Output is a simple method of communication. Currently the shell implements the led and gpiostat commands to use these ports.
Contents
Port Assignments
| Pin | Assignment |
|---|---|
| GPIO 0 | WLAN LED |
| GPIO 1 | Power LED |
| GPIO 2 | Cisco LED White |
| GPIO 3 | Cisco LED Orange |
| GPIO 4 | Cisco Button |
| GPIO 5 | Unkown |
| GPIO 6 | Reset Button |
| GPIO 7 | DMZ LED |
Registers
There are four control and status registers, each which is 2 bytes.
- Input (0xb8000060) - If a GPIO pin is set for output, its input bit is automatically set to 0.
- Output (0xb8000064) - If a GPIO pin is set for input, its output bit is automatically set to 0.
- Enable (0xb8000068) - Determines if a GPIO pin is used for input or output. A bit value of 0 is input and 1 is output.
- Control (0xb800006c) - Usage is currently unknown.
LEDs
Research Notes:
- An LED is enabled by setting its enable bit to 1.
- When an LED is enabled, its input bit becomes 0.
- Once an LED is enabled, if its output bit is 0, the LED is on and if its output bit is 1, the LED is off.
