HD404356 Datasheet, PDF (69/100 Pages) Hitachi Semiconductor – 4-bit HMCS400-Series microcomputer

Port mode register C (PMRC: $025)
HD404358 Series
Bit
Initial value
Read/Write
Bit name
3
0
W
PMRC3
2
1
0
0 Undefined 0
W
W
W
PMRC2 PMRC1 PMRC0
Alarm output function.
Refer to figure 50.
PMRC0
0
1
Serial Clock Division Ratio
Prescaler output divided by 2
Prescaler output divided by 4
PMRC1
0
1
Output Level Control in Idle States
Low level
High level
Figure 56 Port Mode Register C (PMRC)
Serial Data Register (SRL: $006, SRU: $007): This register has the following functions (figures 57 and
58).
• 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 59.
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 57 Serial Data Register (SRL)
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