C8051F312 Silicon Laboratories Inc, C8051F312 Datasheet - Page 222

• Manufacturer Part Number: C8051F312
• Description: IC 8051 MCU 8K FLASH 32LQFP
• Manufacturer: Silicon Laboratories Inc
• Series: C8051F31xr

Specifications of C8051F312

• Core Processor: 8051
• Core Size: 8-Bit
• Speed: 25MHz
• Connectivity: SMBus (2-Wire/I²C), SPI, UART/USART
• Peripherals: POR, PWM, Temp Sensor, WDT
• Number Of I /o: 29
• Program Memory Size: 8KB (8K x 8)
• Program Memory Type: FLASH
• Ram Size: 1.25K x 8
• Voltage - Supply (vcc/vdd): 2.7 V ~ 3.6 V
• Data Converters: A/D 21x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 32-LQFP
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Eeprom Size: -
• Other names: 336-1151

C8051F310/1/2/3/4/5/6/7
19.3. PCA Counter
On “REV A” devices, if the main PCA counter (PCA0H : PCA0L) overflows during the execution phase of a
read-modify-write instruction (bit-wise SETB or CLR, ANL, ORL, XRL) that targets the PCA0CN register,
the CF (Counter Overflow) bit will not be set. An example software work-around is as follows:
This behavior is not present on “REV B” and later devices. Software written for “REV A” devices will run on
“REV B” and later devices without modification.
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Step 1. Disable global interrupts (EA = 0).
Step 2. Read PCA0L. This will latch the value of PCA0H.
Step 3. Read PCA0H, saving the value.
Step 4. Execute the bit-wise operation on CCFn (for example, CLR CCF0, or CCF0 = 0;).
Step 5. Read PCA0L.
Step 6. Read PCA0H, saving the value.
Step 7. If the value of PCA0H read in Step 3 is 0xFF and the value for PCA0H read in Step 6 is
Step 8. Re-enable interrupts (EA = 1).
0x00, then manually set the CF bit in software (for example, SETB CF, or CF = 1;).
Rev. 1.7