Datasheet

Table Of Contents
2002 Microchip Technology Inc. DS30221B-page 101
PIC16F872
FIGURE 11-11: WAKE-UP FROM SLEEP THROUGH INTERRUPT
11.14 In-Circuit Debugger
When the DEBUG bit in the configuration word is
programmed to a 0, the In-Circuit Debugger function-
ality is enabled. This function allows simple debugging
functions when used with MPLAB
®
IDE. When the
microcontroller has this feature enabled, some of the
resources are not available for general use. Table 11-8
shows which features are consumed by the back-
ground debugger.
TABLE 11-8: DEBUGGER RESOURCES
To use the In-Circuit Debugger function of the micro-
controller, the design must implement In-Circuit Serial
Programming connections to MCLR/VPP, VDD, GND,
RB7 and RB6. This will interface to the In-Circuit
Debugger module available from Microchip or one of
the third party development tool companies.
11.15 Program Verification/Code
Protection
If the code protection bit(s) have not been pro-
grammed, the on-chip program memory can be read
out for verification purposes.
11.16 ID Locations
Four memory locations (2000h - 2003h) are designated
as ID locations, where the user can store checksum or
other code identification numbers. These locations are
not accessible during normal execution, but are read-
able and writable during program/verify. It is recom-
mended that only the 4 Least Significant bits of the ID
location are used.
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
OSC1
CLKOUT
(4)
INT pin
INTF Flag
(INTCON<1>)
GIE bit
(INTCON<7>)
INSTRUCTION FLOW
PC
Instruction
Fetched
Instruction
Executed
PC PC+1 PC+2
Inst(PC) = SLEEP
Inst(PC - 1)
Inst(PC + 1)
SLEEP
Processor in
SLEEP
Interrupt Latency
(Note 2)
Inst(PC + 2)
Inst(PC + 1)
Inst(0004h)
Inst(0005h)
Inst(0004h)
Dummy cycle
PC + 2 0004h 0005h
Dummy cycle
T
OST
(2)
PC+2
Note 1: XT, HS or LP oscillator mode assumed.
2: T
OST = 1024TOSC (drawing not to scale). This delay will not be there for RC osc mode.
3: GIE = 1 assumed. In this case, after wake- up, the processor jumps to the interrupt routine.
If GIE = 0, execution will continue in-line.
4: CLKOUT is not available in these osc modes, but shown here for timing reference.
I/O pins RB6, RB7
Stack 1 level
Program Memory Address 0000h must be NOP
Last 100h words
Data Memory 0x070 (0x0F0, 0x170, 0x1F0)
0x1EB - 0x1EF