SNC114
One Channel Direct Drive Speech Controller
5.6. I/O Ports
P1 is a 4-bit input port, P2 and 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
(HꢁL or LꢁH) of P1, P2 and P3 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)
Note: All weak N-MOS’s can serve as pull-low resistors.
4
Ver: 1.3
June 8, 2005