HD404654 Datasheet, PDF (34/111 Pages) Hitachi Semiconductor – 4-Bit Single-Chip Microcomputer

HD404654 Series
System clock select register 1 (SSR1: $029)
Bit
Initial value
Read/Write
Bit name
3
2
1
—
—
0
—
—
W
Not used Not used SSR11
0
0
W
SSR10
× : Don’t care
SSR22 SSR11 SSR10
0
0
0
0
0
1
0
1
0
0
1
1
1
×
×
System clock selection
400 kHz
800 kHz
2 MHz
4 MHz
3.58 MHz
Figure 18 System Clock Select Register 1
System clock select register 2 (SSR2: $02A)
Bit
Initial value
Read/Write
Bit name
3
2
1
0
—
0
—
—
—
W
—
—
Not used SSR22 Not used Not used
SSR22
0
1
System clock selection
Selected from 400 kHz, 800 kHz,
2 MHz, 4 MHz ^*
3.58 MHz
Note: * Refer to system clock select register 1 (SSR1) of figure 18.
Figure 19 System Clock Select Register 2
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