Oki MSM66591, User Manual

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2-6
MSM66591/ML66592 User's Manual
Chapter 2 Description of Pins
2.9 P8_0–P8_7: Input/Output Pins
8-bit I/O pins of Port 8. I/O can be specified in bit units by the Port 8 mode register
(P8IO).
P8_0–P8_7 also function as output pins for internal operations (secondary function).
Secondary functions for P8_0–P8_7 are set in bit units by the Port 8 secondary function
control register (P8SF).
For the pins that have secondary functions set by P8SF, I/O settings by P8IO become
invalid.
<Description of Secondary Functions of Each Pin>
• PWM4 (P8_0)–PWM11 (P8_7)
Output Pins of PWM4–PWM11
At reset (when the
RES
signal is input, the BRK instruction is executed, the watchdog
timer is overflown, or an operation code trap is generated), P8 becomes a high imped-
ance input.
If the
OE
pin (pin 71) is in "L" level when P8 is in output status, these pins output "H" or
"L" level, but if the
OE
pin is in "H" level, these pins go into high impedance status.
2.10 P9_0–P9_7: Input/Output Pins
8-bit I/O pins of Port 9. I/O can be specified in bit units by the Port 9 mode register
(P9IO).
P9_0–P9_7 also functions as an output pin for internal operations (secondary function).
Secondary functions for P9_0–P9_7 are set in bit units by the Port 9 secondary function
control register (P9SF). For the pins that have secondary functions set by P9SF, I/O
settings by P9IO become invalid.
<Description of Secondary Functions of Each Pin>
• RXD2 (P9_0)
Receive data for the receive side serial port 2 is input through this pin.
• TXD2 (P9_1)
Transmit data for the transmit side serial port 2 is output through this pin.
• RXD3 (P9_2)
Receive data for the receive side serial port 3 is input through this pin.
• TXD3 (P9_3)
Transmit data for the transmit side serial port 3 is output through this pin.