sh6636 SinoWealth Micro-Electronics Corp. Ltd, sh6636 Datasheet - Page 6

• Manufacturer Part Number: sh6636
• Description: Mask 4-bit Microcontroller With Remote Control Carrier Synthesizer
• Manufacturer: SinoWealth Micro-Electronics Corp. Ltd

4. Timer
SH6636 has one 8-bit timer. The timer/counter has the following features:
. 8-bit up-counting timer/counter
. Automatically re-loads counter
. 8-bit pre-scaler
. Interrupt on overflow from $FF to $00
The following is a simplified timer block diagram.
(a) Configuration and Operation
Timer0 consists of an 8-bit write-only timer load register
(TL0L, TL0H), and an 8-bit read-only timer counter (TC0L,
TC0H). Each of them has low order digits and high order
digits. Writing data into the timer load register (TL0L, TL0H)
can initialize the timer counter.
Load register programming: Write the low-order digit first and
then the high-order digit. The timer counter is automatically
loaded with the contents of the load register when the high
order digit is written or the counter counts overflow from $FF
to $00.
Timer Load Register: Since register H will control the
physical READ and WRITE operations. Follow these steps:
Write Operation:
Read Operation:
Low nibble first,
High nibble to update the counter
High nibble first,
Followed by Low nibble.
Load Register
TM0 [2:0]
TIMER0
F
OSC
Figure 1. Timer block Diagram
/4
3
6
TIMER0
(8bits)
Figure 2. Timer Load register Configure
Load Reg. L
Latch Reg. L
8-bit timer counter
Load Reg. H
SH6636