E202075_HD404889 Datasheet, PDF (123/202 Pages) Renesas Technology Corp – Low-Voltage AS Microcomputers with On-Chip LCD Circuit

HD404889/HD404899/HD404878/HD404868 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
(øPER/2048)÷2
0
1
Output PSS
(øPER/512)÷2
0
0
Output PSS
(øPER/128)÷2
1
1
Output PSS
(øPER/32)÷2
0
0
Output PSS
(øPER/8)÷2
0
1
Output PSS
(øPER/2)÷2
1
0
Output System clock øPER
1
1
Input External clock
4096 tcyc
1024 tcyc
256 tcyc
64 tcyc
16 tcyc
4 tcyc
tcyc
0
Output PSS
0
(øPER/2048)÷4
1
Output PSS
(øPER/512)÷4
0
0
Output PSS
1
(øPER/128)÷4
1
Output PSS
(øPER/32)÷4
1
0
Output PSS
(øPER/8)÷4
0
1
Output PSS
(øPER/2)÷4
1
0
Output System clock øPER
1
1
Input External clock
8192 tcyc
2048 tcyc
512 tcyc
128 tcyc
32 tcyc
8 tcyc
tcyc
Figure 66 Serial Mode Register 1 (SMR1)
Serial mode register 2 (SMR2: $025):
Serial mode register 2 (SMR2) has the following functions. See figure 67.
• 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.
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