Rainbow Electronics T89C5115 - Manual (Page 16)

16
T89C5115
4128A–8051–04/02
Register Table 12. CKCON Register
CKCON (S:8Fh)
Clock Control Register
Notes: 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 = x000 0000b
7 6 5 4 3 2 1 0
– WDX2 PCAX2 SIX2 T2X2 T1X2 T0X2 X2
Bit
Number
Bit
Mnemonic Description
7 -
Reserved
The value read from this bit is indeterminate. Do not set this bit.
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.