Philips Semiconductors

Product specification

83C576/87C576

80C51 8-bit microcontroller family

8K/256 OTP/ROM, 6 channel 10-bit A/D, 4 comparators,

failure detect circuitry, watchdog timer

1998 Jun 04

13

CMOD Address = OD9H

Reset Value = 00XX X000B

CIDL

WDTE

–

–

–

CPS1

CPS0

ECF

Bit:

Symbol

Function

CIDL

Counter Idle control: CIDL = 0 programs the PCA Counter to continue functioning during idle Mode.

CIDL = 1 programs it to be gated off during idle.

WDTE

Watchdog Timer Enable: WDTE = 0 disables Watchdog Timer function on PCA Module 4. WDTE = 1 enables it.

–

Not implemented, reserved for future use.*

CPS1

PCA Count Pulse Select bit 1.

CPS0

PCA Count Pulse Select bit 0.

CPS1

CPS0

Selected PCA Input**

0

0

0

0

1

1

1

0

2

Timer 0 overflow

1

1

3

ECF

PCA Enable Counter Overflow interrupt:

ECF = 1 enables CF bit in CCON to generate an interrupt. ECF = 0 disables that function of CF.

NOTE:

*

User software should not write 1s to reserved bits. These bits may be used in future 8051 family products to invoke new features. In that case, the reset or inactive value of the

new bit will be 0, and its active value will be 1. The value read from a reserved bit is indeterminate.

SU00686A

7

6

5

432

1

0

Figure 5.

CMOD: PCA Counter Mode Register

CCON Address = OD8H

Reset Value = 00X0 0000B

CF

CR

–

CCF4

CCF3

CCF2

CCF1

CCF0

Bit Addressable

Bit:

Symbol

Function

CF

PCA Counter Overflow flag. Set by hardware when the counter rolls over. CF flags an interrupt if bit ECF in CMOD is

set. CF may be set by either hardware or software but can only be cleared by software.

CR

PCA Counter Run control bit. Set by software to turn the PCA counter on. Must be cleared by software to turn the PCA

counter off.

–

Not implemented, reserved for future use*.

CCF4

PCA Module 4 interrupt flag. Set by hardware when a match or capture occurs. Must be cleared by software.

CCF3

PCA Module 3 interrupt flag. Set by hardware when a match or capture occurs. Must be cleared by software.

CCF2

PCA Module 2 interrupt flag. Set by hardware when a match or capture occurs. Must be cleared by software.

CCF1

PCA Module 1 interrupt flag. Set by hardware when a match or capture occurs. Must be cleared by software.

CCF0

PCA Module 0 interrupt flag. Set by hardware when a match or capture occurs. Must be cleared by software.

NOTE:

*

User software should not write 1s to reserved bits. These bits may be used in future 8051 family products to invoke new features. In that case, the reset or inactive value of the

new bit will be 0, and its active value will be 1. The value read from a reserved bit is indeterminate.

SU00036

76

5

4

3

210

Figure 6.

CCON: PCA Counter Control Register