AT80C51RD2 Atmel Corporation, AT80C51RD2 Datasheet - Page 25

• Manufacturer Part Number: AT80C51RD2
• Manufacturer: Atmel Corporation

Specifications of AT80C51RD2

• Max. Operating Frequency: 60 MHz
• Cpu: 8051-12C
• Max I/o Pins: 32
• Spi: 1
• Uart: 1
• Sram (kbytes): 1.25
• Operating Voltage (vcc): 2.7 to 5.5
• Timers: 4
• Watchdog: Yes

4113D–8051–01/09
Table 10-2.
CCON - PCA Counter Control Register (D8h)
Reset Value = 000X 0000b
Not bit addressable
The watchdog timer function is implemented in module 4 (see Figure 10-4).
The PCA interrupt system is shown in Figure 10-2.
• Bits 0 through 4 are the flags for the modules (bit 0 for module 0, bit 1 for module 1, etc.) and
Number
are set by hardware when either a match or a capture occurs. These flags can only be
cleared by software.
CF
Bit
7
7
6
5
4
3
2
1
0
Mnemonic
CCON Register
CCF4
CCF3
CCF2
CCF1
CCF0
CR
CR
Bit
CF
6
-
Description
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
AT80C51RD2
CCF1
1
CCF0
0
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