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9 pca registers – Rainbow Electronics T89C51AC2 User Manual

Page 75

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75

T89C51AC2

Rev. B – 19-Dec-01

15.9 PCA Registers

Table 36. CMOD Register

CMOD (S:D8h)
PCA Counter Mode Register

Reset Value = 00XX X000b

7

6

5

4

3

2

1

0

CIDL

WDTE

-

-

-

CPS1

CPS0

ECF

Bit

Number

Bit

Mnemonic

Description

7

CIDL

PCA Counter Idle Control bit
Clear to let the PCA run during Idle mode.
Set to stop the PCA when Idle mode is invoked.

6

WDTE

Watchdog Timer Enable
Clear to disable Watchdog Timer function on PCA Module 4,
Set to enable it.

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

CPS1

EWC Count Pulse Select bits
CPS1 CPS0 Clock source
0

0

Internal Clock, FPca/6

0

1

Internal Clock, FPca/2

1

0

Timer 0 overflow

1

1

External clock at ECI/P1.2 pin (Max. Rate = FPca/4)

1

CPS0

0

ECF

Enable PCA Counter Overflow Interrupt bit
Clear to disable CF bit in CCON register to generate an interrupt.
Set to enable CF bit in CCON register to generate an interrupt.