1 operating states in standby mode, Operating states in standby mode – FUJITSU Semiconductor Controller MB89950/950A User Manual

Page 72

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CHAPTER 3 CPU

3.7.1

Operating States in Standby Mode

This section describes the operating states of the CPU and peripheral functions in
standby mode.

Operating states during standby mode

Pin States in Standby Mode

Almost all I/O pins will either keep the state they were placed in, or go to the high-impedance state

according to the pin state control bit of the standby control register (STBC: SPL) just prior to going to the

stop mode. This is true regardless of the clock mode.

See Appendix E "MB89950/950A Series Pin States" for pin states in standby mode.

Table 3.7-1 Operating states of the CPU and peripheral functions in standby mode

Function

Main clock mode

Run

Sleep

Stop

(SPL = "0")

Stop

(SPL = "1")

Main clock

Operating

Operating

Stop

Stop

CPU

Instructions

Operating

Stop

Stop

Stop

ROM

Operating

Hold

Hold

Hold

RAM

Peripheral
functions

I/O ports

Operating

Hold

Hold

Hi-Z

(*1)

Timebase timer

Operating

Operating

Stop

Stop

8-bit PWM timer

Operating

Operating

Stop

Stop

8-bit PWC timer

Operating

Operating

Stop

Stop

Watchdog timer

Operating

Stop

Stop

Stop

LCD controller/driver

Operating

Operating

Stop

Stop

External Interrupts

Operating

Operating

Operating

Operating

Serial I/O

Operating

Operating

Stop

Stop

UART

Operating

Operating

Stop

Stop

*1: If pull-up is selected, it will be "H" level.

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