Owner's manual

A/T8xC5121

4164G–SCR–07/06

LED Ports

Configuration

The current source of the LED Ports can be adjusted to 3 different values: 2, 4 or 10 mA.

The LED output is an alternate function of P3.6 an P3.7 and cannot be used while the

alternate card function is used.

The control register LEDCON is detailed below.

Registers Definition Table 40. LEDCON Register

Reset Value = XXXX 0000b

76543210

----LED1[1]LED1[0]LED0[1]LED0[0]

Bit

Number

Bit

Mnemonic Description

7 - 4 -

Reserved

The value read from this bit is indeterminate. Do not set this bit.

3 - 2 LED1[1,0]

Port LED1 configuration:

LED1[1] LED1[0] Configuration

0 0 Standard C51 port

0 1 2 mA current source when P3.7 is at Low Level

1 0 4 mA current source when P3.7 is at Low Level

1 1 10 mA current source when P3.7 is at Low Level

1 - 0 LED0[1,0]

Port LED0 configuration:

LED0[1] LED0[0] Configuration

0 0 standard C51 port

0 1 2 mA current source when P3.6 is at Low Level

1 0 4 mA current source when P3.6 is at Low Level

1 1 10 mA current source when P3.6 is at Low Level