register, Preliminary, Register – Rainbow Electronics T89C51CC02 User Manual
Page 16
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Rev.A - May 17, 2001
Preliminary
T89C51CC02
6.3. Register
CKCON (S:8Fh)
Clock Control Register
NOTE:
1. This control bit is validated when the CPU clock bit X2 is set; when X2 is low, this bit has no effect.
Reset Value = 0000 0000b
Figure 5. CKCON Register
7
6
5
4
3
2
1
0
CANX2
WDX2
PCAX2
SIX2
T2X2
T1X2
T0X2
X2
Bit Number Bit Mnemonic
Description
7
CANX2
CAN clock (1)
Clear to select 6 clock periods per peripheral clock cycle.
Set to select 12 clock periods per peripheral clock cycle.
6
WDX2
Watchdog clock (1)
Clear to select 6 clock periods per peripheral clock cycle.
Set to select 12 clock periods per peripheral clock cycle.
5
PCAX2
Programmable Counter Array clock (1)
Clear to select 6 clock periods per peripheral clock cycle.
Set to select 12 clock periods per peripheral clock cycle.
4
SIX2
Enhanced UART clock (MODE 0 and 2) (1)
Clear to select 6 clock periods per peripheral clock cycle.
Set to select 12 clock periods per peripheral clock cycle.
3
T2X2
Timer2 clock (1)
Clear to select 6 clock periods per peripheral clock cycle.
Set to select 12 clock periods per peripheral clock cycle.
2
T1X2
Timer1 clock (1)
Clear to select 6 clock periods per peripheral clock cycle.
Set to select 12 clock periods per peripheral clock cycle.
1
T0X2
Timer0 clock (1)
Clear to select 6 clock periods per peripheral clock cycle.
Set to select 12 clock periods per peripheral clock cycle.
0
X2
CPU clock
Clear to select 12 clock periods per machine cycle (STD mode) for CPU and all the peripherals.
Set to select 6 clock periods per machine cycle (X2 mode) and to enable the individual peripherals "X2"bits.