SNC558
Two Channel Direct Drive Speech Controller
5.6. I/O Ports
P1 is a 4-bit input port, P2/P3/P6 are three 4-bit I/O ports and P4/P5 are two 4-bit
output ports. Any bit of P2, P3 and P6 can be programmed as either input or output
port individually. Any valid data transition (H L or L H) of P1, P2, P3 and P6
can reactivate the chip when the chip is in power-down mode.
PAD
To Internal Data Bus
Read Control
Weak
Input Port Configuration (P10~P13)
Port Data
PAD
Port Status
Weak
To Internal Data Bus
Read Control
I/O Port Configuration (P20~P23, P30~P33, P60~P63)
Ver: 1.4
4
June 8, 2005