AT89C51RC2-RLTUL Atmel, AT89C51RC2-RLTUL Datasheet - Page 40

• Manufacturer Part Number: AT89C51RC2-RLTUL
• Description: IC 8051 MCU FLASH 32K 44VQFP
• Manufacturer: Atmel
• Series: 89Cr

Specifications of AT89C51RC2-RLTUL

• Core Processor: 8051
• Core Size: 8-Bit
• Speed: 40MHz
• Connectivity: SPI, UART/USART
• Peripherals: POR, PWM, WDT
• Number Of I /o: 32
• Program Memory Size: 32KB (32K x 8)
• Program Memory Type: FLASH
• Ram Size: 1.25K x 8
• Voltage - Supply (vcc/vdd): 2.7 V ~ 3.6 V
• Oscillator Type: External
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 44-TQFP, 44-VQFP
• Processor Series: AT89x
• Core: 8051
• Data Bus Width: 8 bit
• Data Ram Size: 1280 B
• Interface Type: UART, SPI
• Maximum Clock Frequency: 60 MHz
• Number Of Programmable I/os: 32
• Number Of Timers: 3
• Operating Supply Voltage: 2.7 V to 5.5 V
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• 3rd Party Development Tools: PK51, CA51, A51, ULINK2
• Minimum Operating Temperature: - 40 C
• For Use With: AT89OCD-01 - USB EMULATOR FOR AT8XC51 MCUAT89STK-11 - KIT STARTER FOR AT89C51RX2
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Eeprom Size: -
• Data Converters: -
• Lead Free Status / Rohs Status: Details

16-bit Software Timer/
Compare Mode
Figure 14. PCA Compare Mode and PCA Watchdog Timer
40
CCAPnH
Write to
AT89C51RB2/RC2
1
CCAPnL
Write to
0
Reset
Enable
The PCA Modules can be used as software timers by setting both the ECOM and MAT
bits in the Modules CCAPMn register. The PCA timer will be compared to the Module's
capture registers and when a match occurs, an interrupt will occur if the CCFn (CCON
SFR) and the ECCFn (CCAPMn SFR) bits for the Module are both set (see Figure 14).
Note:
Before enabling ECOM bit, CCAPnL and CCAPnH should be set with a non zero value,
otherwise an unwanted match could occur. Writing to CCAPnH will set the ECOM bit.
Once ECOM set, writing CCAPnL will clear ECOM so that an unwanted match doesn’t
occur while modifying the compare value. Writing to CCAPnH will set ECOM. For this
reason, user software should write CCAPnL first, and then CCAPnH. Of course, the
ECOM bit can still be controlled by accessing to CCAPMn register.
CCAPnH
CH
PCA Counter/Timer
16 bit Comparator
1. Only for Module 4
CIDL
CF
ECOMn
WDTE
CCAPnL
CR
CL
CAPPn
Match
CAPNn MATn TOGn PWMn ECCFn
CCF4
CCF3
CCF2 CCF1 CCF0
CPS1 CPS0
ECF
CCON
0xD8
CCAPMn, n = 0 to 4
0xDA to 0xDE
CMOD
0xD9
PCA IT
RESET
4180E–8051–10/06
(1)