Rainbow Electronics T89C5121 - Manual (Page 11)

11
A/T8xC5121
4164G–SCR–07/06
Figure 6. Push-pull Output Configuration
LED Output Configuration The input only configuration is shown in Figure 7.
Figure 7. LED Source Current Configuration
Note: The port can be configured in quasi bi-directional mode and the level of current can be programmed by means of LEDCON0
and LEDCON1 registers before switching the led on by writing a logical 0 in Port latch.
Input
Pin
Strong
N
P
Port latch
Data
Data
PMOS
NMOS
Pin
Port Latch
Data
Input
Data
LEDx.0
LEDx.1
P
N
N
N
Weak
2 CPU
P
CLOCK DELAY
PMOS
Strong Medium
P
NMOS
LED1CTRL
LED2CTRL