sh66l16a SinoWealth Micro-Electronics Corp. Ltd, sh66l16a Datasheet - Page 13

• Manufacturer Part Number: sh66l16a
• Description: 16k 4-bit Low Power Micro-controller With Lcd Driver
• Manufacturer: SinoWealth Micro-Electronics Corp. Ltd

7. Timer
SH66L16A has one 8-bit timer.
The timer/counter has the following features:
- 8-bit up-counting timer/counter.
- Automatic re-load counter.
- 8-level prescaler.
- Interrupt on overflow from $FF to $00.
The following is a simplified timer block diagram.
The timers provide the following functions:
- Programmable interval timer function.
- Read counter value.
7.1. Timer0 Configuration and Operation
The Timer0 consist 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.
7.2 Timer0 Mode Register
The timer can be programmed in several different prescalers by setting Timer Mode register (T0M).
The clock source pre-scale by the 8-level counter first, then generate the output plus to timer counter. The Timer Mode registers
(T0M) are 3-bit registers used for the timer control as shown in Table 1.
Table 1: Timer0 Mode Register ($02)
System
T0M.2
clock
0
0
0
0
1
1
1
1
T0M.1
TM.2
0
0
1
1
0
0
1
1
Prescaler
t
TM.1
osc
T0M.0
TM.0
0
1
0
1
0
1
0
1
SYNC
Prescaler Divide Ratio
COUNTER
8-BIT
/2
/2
/2
/2
/2
/2
/2
/2
11
9
7
5
3
2
1
0
13
Clock Source
System clock
System clock
System clock
System clock
System clock
System clock
System clock
System clock
The low-order digit should be written 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 counter counts overflow from $FF to $00.
Timer Load Register: The register H controls the physical
READ and WRITE operations.
Please follow these steps:
Write Operation:
Read Operation:
Low nibble first
High nibble to update the counter
High nibble first
Low nibble followed.
Load Reg. L
Latch Reg. L
8-bit timer counter
Load Reg. H
SH66L16A