2 POWER SUPPLY, RESET, AND CLOCKS
S1C17M20/M21/M22/M23/M24/M25
Seiko Epson Corporation
2-21
TECHNICAL MANUAL (Rev. 1.0)
CLG FOUT Control Register
Register name
Bit
Bit name
Initial
Reset
R/W
Remarks
CLGFOUT
15–8 –
0x00
–
R
–
7
–
0
–
R
6–4 FOUTDIV[2:0]
0x0
H0
R/W
3–2 FOUTSRC[1:0]
0x0
H0
R/W
1
–
0
–
R
0
FOUTEN
0
H0
R/W
Bits 15–7 Reserved
Bits 6–4
FOUTDIV[2:0]
These bits set the FOUT clock division ratios.
Bits 3–2
FOUTSRC[1:0]
These bits select the FOUT clock sources.
Table 2.6.11 FOUT Clock Source and Division Ratio Settings
CLGFOUT.
FOUTDIV[2:0] bits
CLGFOUT.FOUTSRC[1:0] bits
0x0
0x1
0x2
0x3
IOSCCLK
OSC1CLK
OSC3CLK
SYSCLK
0x7
1/128
1/32,768
1/128
Reserved
0x6
1/64
1/4,096
1/64
Reserved
0x5
1/32
1/1,024
1/32
Reserved
0x4
1/16
1/256
1/16
Reserved
0x3
1/8
1/8
1/8
Reserved
0x2
1/4
1/4
1/4
Reserved
0x1
1/2
1/2
1/2
Reserved
0x0
1/1
1/1
1/1
1/1
Note
: When the CLGFOUT.FOUTSRC[1:0] bits are set to 0x3, the FOUT output will be stopped in
SLEEP/HALT mode as SYSCLK is stopped.
Bit 1
Reserved
Bit 0
FOUTEN
This bit controls the FOUT clock external output.
1 (R/W): Enable external output
0 (R/W): Disable external output
Note
: Since the FOUT signal generated is out of sync with writings to the CLGFOUT.FOUTEN bit,
a glitch may occur when the FOUT output is enabled or disabled.