HD404829R Datasheet, PDF (93/149 Pages) Renesas Technology Corp – AS Microcomputer Incorporating a LCD controller/Driver Circuit

Serial mode register B (SMRB: $028)
Bit
Initial value
Read/Write
Bit name
3
2
1
0
—
— Undefined 0
—
—
W
W
Not used Not used SMRB1 SMRB0
HD404829R Series
SMRB1
0
1
Output level control in idle states
Low level
High level
SMRB0
0
1
Transmit clock division ratio
Prescaler output divided by 2
Prescaler output divided by 4
Figure 75 Serial Mode Register B (SMRB)
Serial Data Register (SRL: $006, SRU: $007): This register has the following functions (figures 76 and
77).
• Transmission data write and shift
• Receive data shift and read
Writing data in this register is output from the SO pin, LSB first, synchronously with the falling edge of the
transmit clock; data is input, LSB first, through the SI pin at the rising edge of the transmit clock.
Input/output timing is shown in figure 78.
Data cannot be read or written during serial data transfer. If a read/write occurs during transfer, the
accuracy of the resultant data cannot be guaranteed.
Serial data register (lower digit) (SRL: $006)
Bit
Initial value
Read/Write
Bit name
3
2
1
0
Undefined Undefined Undefined Undefined
R/W
R/W
R/W
R/W
SR3
SR2
SR1
SR0
Figure 76 Serial Data Register (SRL)
Serial data register (upper digit) (SRU: $007)
Bit
Initial value
Read/Write
Bit name
3
2
1
0
Undefined Undefined Undefined Undefined
R/W
R/W
R/W
R/W
SR7
SR6
SR5
SR4
Figure 77 Serial Data Register (SRU)
91