sh66p51 SinoWealth Micro-Electronics Corp. Ltd, sh66p51 Datasheet - Page 21

• Manufacturer Part Number: sh66p51
• Description: Otp 2k 4-bit Micro-controller With Lcd Driver
• Manufacturer: SinoWealth Micro-Electronics Corp. Ltd

8. Remote Control Carrier Synthesizer
The device has a built-in carrier synthesizer for infrared or RF remote control circuits.
System Register:
The carrier synthesizer can be programmed in several different pre-scaler ratios by setting CPS2 - 0.
The carrier-generating counter is an 8-bit count-up counter and two 8-bit data load registers (High level data register and
Low level data register). Writing data into the data load registers can initialize the counter.
After system reset, the counter is automatically loaded with the contents of high level data register and output high level at
the same time. Following when counter counts overflow from $FF to $00,the counter is automatically loaded with the
contents of low level data register and output low level at the same time. When counter counts overflow again from $FF to
$00 again, the counter will be loaded with the contents of high level data register again. The above sequences make up a
complete loop. So the carrier synthesizer can output continuous carrier wave of certain duties and certain period.
If REMO is set to “1” from “0”, the carrier counter will be initialized to load high level data register and output high level
whatever states the counter is.
Load register programming: User can modify low level data register to change the width of the low level or modify high level
data register to change the width of high level. In the way the carrier synthesizer can output carrier wave of different duties
and different period.
REM will remain outputting carrier wave in HALT mode, but will output GND in STOP mode.
Address
$0D
$13
CPS2
0
0
0
0
1
1
1
1
PULLEN
Bit3
-
CPS1
0
0
1
1
0
0
1
1
CPS2
Bit2
-
CPS0
0
1
0
1
0
1
0
1
CPS1
Bit1
-
REMO
Pre-scaler Divide Ratio
CPS0
REM
Bit0
System clock/2
System clock/2
System clock/2
System clock/2
System clock/2
System clock/2
System clock/2
System clock/2
R/W
R/W
W
R
21
Bit2-0: Carrier counter source pre-divider
Bit3: Port pull high enable control
Bit0: REMO output data
Bit0: REM pin output status
11
9
7
5
3
2
1
0
Remarks
Ratio N
2048
512
128
32
8
4
2
1
SH66P51