4.10.2. LED control register

The LED_LIGHTS register controls four of the LEDs on the Integrator/CP. The LEDs are attached to bit ports provided by the alphanumeric display. Accesses to these bit ports are managed by the FPGA. Application programs write appropriate values into the LED_LIGHTS register, and the FPGA carries out the necessary transfer to turn the LEDs ON or OFF.

You must allow each transfer to the alphanumeric display to complete before writing new data to the display. Use the following sequence:

  1. Check the display status is IDLE (bit 0 = 0) in the LED_ALPHA register.

  2. Write a value to the LED_LIGHTS register.

Note

The data from the LED_LIGHTS register is transferred as a serial bit-stream into the alphanumeric display at the same time as the character data in LED_ALPHA.

The bit assignments for the LED_LIGHTS register are shown in Table 4.25.

Table 4.25. LED_LIGHTS register

Bit

Type

Function

3

Read/write

LED3:

0 = OFF

1 = ON

2

Read/write

LED2:

0 = OFF

1 = ON

1

Read/write

LED1:

0 = OFF

1 = ON

0

Read/write

LED0:

0 = OFF

1 = ON

See Baseboard LEDs for the location and function of the LEDs.

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