
10
4431E–8051–04/06
AT/TS8xC54/8X2
Table 6-1.
CKCON Register
CKCON - Clock Control Register (8Fh)
Reset Value = XXXX XXX0b
Not bit addressable
F or further details on the X2 fe ature, please refer to ANM 072 ava ilable on the web
(http://www.atmel.com)
76
543
210
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-
X2
Bit
Number
Bit
Mnemonic
Description
7-
Reserved
The value read from this bit is indeterminate. Do not set this bit.
6-
Reserved
The value read from this bit is indeterminate. Do not set this bit.
5-
Reserved
The value read from this bit is indeterminate. Do not set this bit.
4-
Reserved
The value read from this bit is indeterminate. Do not set this bit.
3-
Reserved
The value read from this bit is indeterminate. Do not set this bit.
2-
Reserved
The value read from this bit is indeterminate. Do not set this bit.
1-
Reserved
The value read from this bit is indeterminate. Do not set this bit.
0X2
CPU and peripheral clock bit
Clear to select 12 clock periods per machine cycle (STD mode, FOSC=FXTAL/2).
Set to select 6 clock periods per machine cycle (X2 mode, FOSC=FXTAL).