PIC16LC923-04I/L Microchip Technology, PIC16LC923-04I/L Datasheet - Page 115

• Manufacturer Part Number: PIC16LC923-04I/L
• Description: IC,MICROCONTROLLER,8-BIT,PIC CPU,CMOS,LDCC,68PIN,PLASTIC
• Manufacturer: Microchip Technology
• Series: PIC® 16Cr

Specifications of PIC16LC923-04I/L

• Rohs Compliant: YES
• Core Processor: PIC
• Core Size: 8-Bit
• Speed: 4MHz
• Connectivity: I²C, SPI
• Peripherals: LCD, POR, PWM, WDT
• Number Of I /o: 25
• Program Memory Size: 7KB (4K x 14)
• Program Memory Type: OTP
• Ram Size: 176 x 8
• Voltage - Supply (vcc/vdd): 2.5 V ~ 6 V
• Oscillator Type: External
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 68-PLCC
• Processor Series: PIC16LC
• Core: PIC
• Data Bus Width: 8 bit
• Data Ram Size: 176 B
• Interface Type: I2C, SPI
• Maximum Clock Frequency: 8 MHz
• Number Of Programmable I/os: 25
• Number Of Timers: 3
• Operating Supply Voltage: 2.5 V to 6 V
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• 3rd Party Development Tools: 52715-96, 52716-328, 52717-734
• Development Tools By Supplier: ICE2000
• Minimum Operating Temperature: - 40 C
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Eeprom Size: -
• Data Converters: -
• Lead Free Status / Rohs Status: Details

14.5.1
External interrupt on RB0/INT pin is edge triggered:
either rising if bit INTEDG (OPTION<6>) is set, or fall-
ing, if the INTEDG bit is clear. When a valid edge
appears
(INTCON<1>) is set. This interrupt can be disabled by
clearing enable bit INTE (INTCON<4>). Flag bit INTF
must be cleared in software in the interrupt service rou-
tine before re-enabling this interrupt. The INT interrupt
can wake-up the processor from SLEEP, if bit INTE was
set prior to going into SLEEP. The status of global inter-
rupt enable bit GIE decides whether or not the proces-
sor branches to the interrupt vector following wake-up.
See Section 14.8 for details on SLEEP mode.
14.5.2
An overflow (FFh
flag bit T0IF (INTCON<2>). The interrupt can be
enabled/disabled by setting/clearing enable bit T0IE
(INTCON<5>). (Section 7.0)
14.5.3
An input change on PORTB<7:4> sets flag bit RBIF
(INTCON<0>). The interrupt can be enabled/disabled
by setting/clearing enable bit RBIE (INTCON<4>).
(Section 5.2)
EXAMPLE 14-1: SAVING STATUS, W, AND PCLATH REGISTERS IN RAM
1997 Microchip Technology Inc.
MOVWF
SWAPF
CLRF
MOVWF
MOVF
MOVWF
CLRF
BCF
MOVF
MOVWF
:
:(ISR)
:
MOVF
MOVWF
SWAPF
MOVWF
SWAPF
SWAPF
INT INTERRUPT
TMR0 INTERRUPT
PORTB INTCON CHANGE
on
the
W_TEMP
STATUS,W
STATUS
STATUS_TEMP
PCLATH, W
PCLATH_TEMP
PCLATH
STATUS, IRP
FSR, W
FSR_TEMP
PCLATH_TEMP, W
PCLATH
STATUS_TEMP,W
STATUS
W_TEMP,F
W_TEMP,W
00h) in the TMR0 register will set
RB0/INT
pin,
flag
;Copy W to TEMP register, could be bank one or zero
;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
;Only required if using pages 1, 2 and/or 3
;Save PCLATH into W
;Page zero, regardless of current page
;Return to Bank 0
;Copy FSR to W
;Copy FSR from W to FSR_TEMP
;Restore PCLATH
;Move W into PCLATH
;Swap STATUS_TEMP register into W
;(sets bank to original state)
;Move W into STATUS register
;Swap W_TEMP
;Swap W_TEMP into W
bit
INTF
14.6
During an interrupt, only the return PC value is saved
on the stack. Typically, users may wish to save key reg-
isters during an interrupt i.e., W register and STATUS
register. This will have to be implemented in software.
Example 14-1 stores and restores the STATUS, W, and
PCLATH registers. The register, W_TEMP, must be
defined in each bank and must be defined at the same
offset from the bank base address (i.e., if W_TEMP is
defined at 0x20 in bank 0, it must also be defined at
0xA0 in bank 1).
The example:
a)
b)
c)
d)
e)
f)
Stores the W register.
Stores the STATUS register in bank 0.
Stores the PCLATH register.
Executes the ISR code.
Restores the STATUS register (and bank select
bit).
Restores the W and PCLATH registers.
Context Saving During Interrupts
PIC16C9XX
DS30444E - page 115