PIC16F688-E/ST Microchip Technology, PIC16F688-E/ST Datasheet - Page 114

• Manufacturer Part Number: PIC16F688-E/ST
• Description: IC MCU FLASH 4KX14 14TSSOP
• Manufacturer: Microchip Technology
• Series: PIC® 16Fr

Specifications of PIC16F688-E/ST

• Program Memory Type: FLASH
• Program Memory Size: 7KB (4K x 14)
• Package / Case: 14-TSSOP
• Core Processor: PIC
• Core Size: 8-Bit
• Speed: 20MHz
• Connectivity: UART/USART
• Peripherals: Brown-out Detect/Reset, POR, WDT
• Number Of I /o: 12
• Eeprom Size: 256 x 8
• Ram Size: 256 x 8
• Voltage - Supply (vcc/vdd): 2 V ~ 5.5 V
• Data Converters: A/D 8x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 125°C
• Processor Series: PIC16F
• Core: PIC
• Data Bus Width: 8 bit
• Data Ram Size: 256 B
• Interface Type: SCI/USART
• Maximum Clock Frequency: 20 MHz
• Number Of Programmable I/os: 12
• Number Of Timers: 2
• Operating Supply Voltage: 2 V to 5.5 V
• Maximum Operating Temperature: + 125 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, DM163014, DM164120-4
• Minimum Operating Temperature: - 40 C
• On-chip Adc: 8-ch x 10-bit
• Data Rom Size: 256 B
• Height: 0.9 mm
• Length: 5 mm
• Supply Voltage (max): 5.5 V
• Supply Voltage (min): 2 V
• Width: 4.4 mm
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• For Use With: XLT14SS-1 - SOCKET TRANSITION 14DIP/14SSOPAC162061 - HEADER INTRFC MPLAB ICD2 20PINAC162056 - HEADER INTERFACE ICD2 16F688
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

PIC16F688
11.6
During an interrupt, only the return PC value is saved
on the stack. Typically, users may wish to save key
registers during an interrupt (e.g., W and Status
registers). This must be implemented in software.
Since the lower 16 bytes of all banks are common in the
PIC16F688 (see Figure 2-2), temporary holding
registers, W_TEMP and STATUS_TEMP, should be
placed in here. These 16 locations do not require
banking and therefore, make it easier to context save
and restore. The same code shown in Example 11-1
can be used to:
• Store the W register
• Store the Status register
• Execute the ISR code
• Restore the Status (and Bank Select Bit register)
• Restore the W register
EXAMPLE 11-1:
DS41203B-page 112
Note:
MOVWF
SWAPF
CLRF
MOVWF
:
:(ISR)
:
SWAPF
MOVWF
SWAPF
SWAPF
Context Saving During Interrupts
The PIC16F688 normally does not require
saving
computed GOTO’s are used in the ISR and
the main code, the PCLATH must be
saved and restored in the ISR.
W_TEMP
STATUS,W
STATUS
STATUS_TEMP
STATUS_TEMP,W
STATUS
W_TEMP,F
W_TEMP,W
the
SAVING STATUS AND W REGISTERS IN RAM
PCLATH.
;Copy W to TEMP register
;Swap status to be saved into W
;bank 0, regardless of current bank, Clears IRP,RP1,RP0
;Save status to bank zero STATUS_TEMP register
;Insert user code here
;Swap STATUS_TEMP register into W
;(sets bank to original state)
;Move W into Status register
;Swap W_TEMP
;Swap W_TEMP into W
However,
Preliminary
if
 2004 Microchip Technology Inc.