SNC21120
1-CH H.Q. Speech Controller
5.6
I/O Ports
There are four 4-bit I/O ports P1, P2, P3 and P6. Any I/O can be individually
programmed as either input pull low or output. Any valid data transition (HꢂL or
LꢂH) of P1, P2, P3 and P6 can reactivate the chip when it is in power-down stage.
Port Data
PAD
Port Status
Weak
To Internal Data Bus
Read Control
I/O Port Configuration
Note:
(1) Weak N-MOS can serve as pull-low resistor.
(2) The driving/sink current of P3.3 & P3.2 is up to 8mA/16mA
5.7
IR Function
Bit 3 of Mode Register is applied to control the IR function. P33 can be modulated with
38.5KHz square wave before sent out to P3.3 or P2.3 pin. P3.3 and P2.3 out is
controlled by Mode1.1. If Mode1.1 set 1 IR is use P2.3, set “0” is use P3.3. The IR
signal can be achieved by this modulated signal.
5.8
PWM IO control
SNC21120 have support 4 PWM IO (P30~P33). Each I/O has 8 bits independent duty
register.
5.9
Watch Dog Timer
SNC21120 built an internal WDT (Watch Dog Timer). This Watchdog timer would
issue resets signal to this chip if it is not cleared before reaching terminal count (1sec).
The watchdog timer is enabled at reset and cannot be disabled.
6
Ver: 1.0
November 08, 2006
SONIX [ SONIX TECHNOLOGY COMPANY ]
