FUJITSU Semiconductor Controller MB89950/950A User Manual

Page 95

Advertising
background image

81

CHAPTER 4 I/O PORTS

Operation in stop mode

The output transistors are forcibly turned "OFF" regardless of the PRD0 register value and 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. Moreover, to avoid leakage (from floating input pin), input must

be driven by either "1" or "0" when SPL = "1".

Table 4.3-4 "Port 1 pin state" lists the port 1 pin states.

Table 4.3-4 Port 1 pin state

Pin name

Normal operation

sleep mode

stop mode (SPL = "0")

Stop mode (SPL = "1")

Reset

P10/SEG28 to P17/SEG35

General-purpose I/O ports/segment
driver output

Hi-Z

Hi-Z

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

Advertising