FUJITSU Semiconductor Controller MB89950/950A User Manual

Page 111

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CHAPTER 4 I/O PORTS

Operation in stop mode

The pins go to the high-impedance state, if the pin state specification bit in the standby control register

(STBC: SPL) is "1" when the device goes to stop mode. This is achieved by forcibly setting the output

transistor "OFF" regardless of the DDR4 register value.

Table 4.6-4 "Port 4 pin state" lists the port 4 pin states.

Reference:

Pins with a pull-up resistor go to the "H" level (pull-up state) rather than to the high-impedance state

when the output transistor is turned "OFF".

Table 4.6-4 Port 4 pin state

Pin name

Normal operation

sleep mode

stop mode (SPL = "0")

Stop mode (SPL = "1")

Reset

P40 to P46/INT0

General-purpose I/O port/peripheral I/O

Hi-Z

Hi-Z

SPL: Pin state specification bit in the standby control register (STBC)
Hi-Z: High impedance

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