AT89C51RB2-RLTCM ATMEL [ATMEL Corporation], AT89C51RB2-RLTCM Datasheet - Page 32

• Manufacturer Part Number: AT89C51RB2-RLTCM
• Description: 8-bit Microcontroller with 16K/ 32K Bytes Flash
• Manufacturer: ATMEL [ATMEL Corporation]

32
AT89C51RB2/RC2
Table 23. CCON Register
CCON – PCA Counter Control Register (D8h)
Reset Value = 000X 0000b
Not bit addressable
The watchdog timer function is implemented in Module 4 (see Figure 13).
The PCA interrupt system is shown in Figure 11.
Number
CF
Bit
7
7
6
5
4
3
2
1
0
Mnemonic Description
CCF4
CCF3
CCF2
CCF1
CCF0
CR
Bit
CR
CF
6
-
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.
PCA Counter Run Control Bit
Must be cleared by software to turn the PCA counter off.
Set by software to turn the PCA counter on.
Reserved
The value read from this bit is indeterminate. Do not set this bit.
PCA Module 4 Interrupt Flag
Must be cleared by software.
Set by hardware when a match or capture occurs.
PCA Module 3 Interrupt Flag
Must be cleared by software.
Set by hardware when a match or capture occurs.
PCA Module 2 Interrupt Flag
Must be cleared by software.
Set by hardware when a match or capture occurs.
PCA Module 1 Interrupt Flag
Must be cleared by software.
Set by hardware when a match or capture occurs.
PCA Module 0 Interrupt Flag
Must be cleared by software.
Set by hardware when a match or capture occurs.
5
-
CCF4
4
CCF3
3
CCF2
2
CCF1
1
4180B–8051–04/03
CCF0
0