TS80C51RA2 Atmel Corporation, TS80C51RA2 Datasheet - Page 24

• Manufacturer Part Number: TS80C51RA2
• Description: High Performance 8-bit Microcontroller
• Manufacturer: Atmel Corporation

24
TS8xC51Rx2
The CMOD SFR includes three additional bits associated with the PCA (See Figure 7
and Table 8).
•
•
•
The CCON SFR contains the run control bit for the PCA and the flags for the PCA timer
(CF) and each module (Refer to Table 9).
•
•
•
Table 9. CCON: PCA Counter Control Register
1.
The watchdog timer function is implemented in module 4 (See Figure 10).
CF
CR
-
CCF4
CCF3
CCF2
CCF1
CCF0
Symbol
The CIDL bit which allows the PCA to stop during idle mode.
The WDTE bit which enables or disables the watchdog function on module 4.
The ECF bit which when set causes an interrupt and the PCA overflow flag CF (in
the CCON SFR) to be set when the PCA timer overflows.
Bit CR (CCON.6) must be set by software to run the PCA. The PCA is shut off by
clearing this bit.
Bit CF: The CF bit (CCON.7) is set when the PCA counter overflows and an
interrupt will be generated if the ECF bit in the CMOD register is set. The CF bit can
only be cleared by software.
Bits 0 through 4 are the flags for the modules (bit 0 for module 0, bit 1 for module 1,
etc.) and are set by hardware when either a match or a capture occurs. These flags
also can only be cleared by software.
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.
Address 0D8H
CCON
Function
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. 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.
PCA Module 4 interrupt flag. Set by hardware when a match or capture occurs. Must be
cleared by software.
PCA Module 3 interrupt flag. Set by hardware when a match or capture occurs. Must be
cleared by software.
PCA Module 2 interrupt flag. Set by hardware when a match or capture occurs. Must be
cleared by software.
PCA Module 1 interrupt flag. Set by hardware when a match or capture occurs. Must be
cleared by software.
PCA Module 0 interrupt flag. Set by hardware when a match or capture occurs. Must be
cleared by software.
Reset value
CF
0
CR
0
-
X
(1)
CCF4
0
CCF3
0
CCF2
0
4188A–8051–10/02
CCF1
0
CCF0
0