PD17202AGF-011_15 Datasheet, PDF (16/30 Pages) Renesas Technology Corp – 4-BIT SINGLE-CHIP MICROCONTROLLER WITH LCD CONTROLLER/DRIVER AND KEY SCAN CIRCUIT FOR FPC (FRONT PANEL CONTROLLER)

µPD17202AGF-011
5.1 Serial Data Input
The serial data is input in synchronization with the rising of the CLOCK pin (pin 27) in the input status (the initial
status is “input”).
The last 4 bits read at the rising edge of the LOAD pin (pin 28) are identified and processed as a command.
Figure 5-2 shows the timing chart of serial data input.
Table 5-1 lists the serial data I/O commands.
Figure 5-2. Timing Chart of Serial Data Input
CLOCK
DATA
LSB
D0
D1
MSB
b0
b1
b2
b3
Input data
(Last 4 bits are serial data input command)
LOAD
Table 5-1. Serial Data I/O Commands
b3
0
0
0
0
0
1
1
Others
Command
b2
b1
0
1
0
1
1
0
1
1
1
1
1
0
1
1
Operation
b0
0
Inputs display data (data A)
1
Inputs display data (data B)
×
Outputs key data
0
Inputs display data (A) + outputs key data
1
Inputs display data (B) + outputs key data
×
Outputs key data
×
Outputs key data
Setting prohibited
×: Undefined
Remarks 1. For the data configuration of display data input, refer to 4. LCD DISPLAY FUNCTION.
2. For the data configuration of key data output, refer to 3. KEY SCAN.
3. Execute display data input before key data output.
4. If a pulse is input to the LOAD pin without display data input, the device does not
operate.
5. The device does not operate when data other than an I/O command is input.
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