SNC532

Two Channel Direct Drive Speech Controller

5.6. I/O Ports

P1 is a 4-bit input port and P2/P3 are two 4-bit I/O ports. Any bit of P2 and P3 can

be programmed as either input or output port individually. Any valid data transition

(H

L or L H) of P1, P2 and P3 can reactivate the chip when the chip is in

power-down mode.

To Internal Data Bus

Read Control

PAD

Weak

Input Port Configuration (P10~P13)

Port Data

Port Status

To Internal Data Bus

Read Control

PAD

Weak

I/O Port Configuration (P20~P23, P30~P33)

Note: weak N-MOS’s can serve as pull-low resistors.

Ver: 1.2

November 26, 2002

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