PIC16F877A-I/ML Microchip Technology, PIC16F877A-I/ML Datasheet - Page 135

• Manufacturer Part Number: PIC16F877A-I/ML
• Description: IC MCU FLASH 8KX14 A/D 44QFN
• Manufacturer: Microchip Technology
• Series: PIC® 16Fr

Specifications of PIC16F877A-I/ML

• Core Size: 8-Bit
• Program Memory Size: 14KB (8K x 14)
• Core Processor: PIC
• Speed: 20MHz
• Connectivity: I²C, SPI, UART/USART
• Peripherals: Brown-out Detect/Reset, POR, PWM, WDT
• Number Of I /o: 33
• Program Memory Type: FLASH
• Eeprom Size: 256 x 8
• Ram Size: 368 x 8
• Voltage - Supply (vcc/vdd): 4 V ~ 5.5 V
• Data Converters: A/D 8x10b
• Oscillator Type: External
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 44-QFN
• Controller Family/series: PIC16F
• No. Of I/o's: 33
• Eeprom Memory Size: 256Byte
• Ram Memory Size: 368Byte
• Cpu Speed: 20MHz
• No. Of Timers: 3
• Processor Series: PIC16F
• Core: PIC
• Data Bus Width: 8 bit
• Data Ram Size: 368 B
• Interface Type: I2C, SPI, USART
• Maximum Clock Frequency: 20 MHz
• Number Of Programmable I/os: 33
• Number Of Timers: 1 x 16 bit
• Operating Supply Voltage: 2 V to 5.5 V
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• 3rd Party Development Tools: 52715-96, 52716-328, 52717-734
• Development Tools By Supplier: PG164130, DV164035, DV244005, DV164005, PG164120, ICE2000, DM163022, DV164120
• Minimum Operating Temperature: - 40 C
• On-chip Adc: 8
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• For Use With: XLT44QFN2 - SOCKET TRAN ICE 44QFN/40DIPAC164322 - MODULE SOCKET MPLAB PM3 28/44QFN444-1001 - DEMO BOARD FOR PICMICRO MCU
• Lead Free Status / Rohs Status: Details

1997 Microchip Technology Inc.
Example 8-3
RAM only in Bank0 (such as the PIC16C620). The Bank must be tested before saving any of the
user registers. , W_TEMP, must be defined across all banks and must be defined at the same
offset from the bank base address. The user register, STATUS_TEMP, must be defined in Bank0.
The steps of
1.
2.
3.
4.
5.
6.
If additional locations need to be saved before executing the Interrupt Service Routine (ISR)
code, they should be saved after the STATUS register is saved (step 2), and restored before the
STATUS register is restored (step 4).
Example 8-3: Saving the STATUS and W Registers in RAM
Push
RP0CLEAR
;
ISR_Code
;
Pop
Restore_WREG
Test current bank.
Stores the W register regardless of current bank.
Stores the STATUS register in Bank0.
Executes the Interrupt Service Routine (ISR) code.
Restores the STATUS (and bank select bit register).
Restores the W register.
BTFSS
GOTO
BCF
MOVWF
SWAPF
MOVWF
BSF
GOTO
MOVWF
SWAPF
MOVWF
:
: (Interrupt Service Routine (ISR) )
:
SWAPF
MOVWF
BTFSS
GOTO
BCF
SWAPF
SWAPF
BSF
RETFIE
SWAPF
SWAPF
RETFIE
Example
stores and restores the STATUS and W registers for devices with general purpose
(for Devices with General Purpose RAM Only in Bank0)
STATUS, RP0
RP0CLEAR
STATUS, RP0
W_TEMP
STATUS, W
STATUS_TEMP
STATUS_TEMP, 1
ISR_Code
W_TEMP
STATUS, W
STATUS_TEMP
STATUS_TEMP, W
STATUS
STATUS, RP0
Restore_WREG
STATUS, RP0
W_TEMP, F
W_TEMP, W
STATUS, RP0
W_TEMP, F
W_TEMP, W
8-3:
Section 8. Interrupts
; In Bank 0?
; YES,
; NO, Force to Bank 0
; Store W register
; Swap STATUS register and
;
; Set the bit that corresponds to RP0
; Push completed
; Store W register
; Swap STATUS register and
;
; Restore Status register
;
; In Bank 1?
; NO,
; YES, Force Bank 0
; Restore W register
;
; Back to Bank 1
; POP completed
; Restore W register
;
; POP completed
store in STATUS_TEMP
store in STATUS_TEMP
DS31008A-page 8-13
8