HD404374 Datasheet, PDF (99/161 Pages) Renesas Technology Corp – Low-Voltage AS Microcomputers with On-Chip A/D Converter

HD404374/HD404384/HD404389/HD404082/HD404084 Series
Serial mode register 1 (SMR1: $024)
Bit
3
2
1
0
Read/Write
W
W
W
W
Initial value on reset 0
0
0
0
Bit name
SMR13 SMR12 SMR11 SMR10
SMR13 SMR12 SMR11 SMR10 SCK pin ^{Serial clock}
Serial clock
Serial clock
source (PSS division ratio + 2 or 4) cycle
0
Output PSS
( PER/2048)+2
0
1
Output PSS
( PER/512)+2
0
0
Output PSS
( PER/128)+2
1
1
Output PSS
( PER/32)+2
0
0
Output PSS
( PER/8)+2
0
1
Output PSS
( PER/2)+2
1
0
Output System clock PER
1
1
Input External clock
4096 tcyc
1024 tcyc
256 tcyc
64 tcyc
16 tcyc
4 tcyc
tcyc
0
Output PSS
0
( PER/2048)+4
1
Output PSS
( PER/512)+4
0
0
Output PSS
1
( PER/128)+4
1
Output PSS
( PER/32)+4
1
0
Output PSS
0
( PER/8)+4
1
Output PSS
( PER/2)+4
1
0
Output System clock PER
1
1
Input External clock
8192 tcyc
2048 tcyc
512 tcyc
128 tcyc
32 tcyc
8 tcyc
tcyc
Figure 56 Serial Mode Register 1 (SMR1)
Serial mode register 2 (SMR2: $025):
Serial mode register 2 (SMR2) has the following functions. See figure 57.
• R2₂/SI/SO pin PMOS control
• Idle high/low control
Serial mode register 2 (SMR2) is a 2-bit write-only register. The register value cannot be modified in the
transfer state.
Bit 2 (SMR22) of serial mode register 2 (SMR2) controls the on/off status of the R2₂/SI/SO pin PMOS.
The bit 2 (SMR22) only is reset to 0 by an MCU reset.
Bit 1 (SMR21) of serial mode register 2 (SMR2) performs SO pin high/low control in the idle state. The
SO pin changes at the same time as the high/low write.
Rev.5.00, Sep.11.2003, page 99 of 161