PIC16F7X Datasheet, PDF (105/174 Pages) Microchip Technology – 28/40-Pin 8-Bit CMOS FLASH Microcontrollers

PIC16F7X
FIGURE 12-12: WAKE-UP FROM SLEEP THROUGH INTERRUPT
OSC1
CLKOUT⁽⁴⁾
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
TOST⁽²⁾
INT pin
INTF Flag
(INTCON<1>)
GIE bit
(INTCON<7>)
INSTRUCTION FLOW
PC
Instruction
Fetched
Instruction
Executed
PC
Inst(PC) = SLEEP
Inst(PC - 1)
PC+1
Inst(PC + 1)
SLEEP
Processor in
SLEEP
PC+2
Interrupt Latency
(Note 2)
PC+2
Inst(PC + 2)
Inst(PC + 1)
PC + 2
Dummy cycle
0004h
Inst(0004h)
Dummy cycle
0005h
Inst(0005h)
Inst(0004h)
Note 1: XT, HS or LP oscillator mode assumed.
2: TOST = 1024 TOSC (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.
12.15 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.
12.16 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.
12.17 In-Circuit Serial Programming
PIC16F7X microcontrollers can be serially pro-
grammed while in the end application circuit. This is
simply done, with two lines for clock and data and three
other lines for power, ground, and the programming
voltage (see Figure 12-13 for an example). This allows
customers to manufacture boards with unprogrammed
devices, and then program the microcontroller just
before shipping the product. This also allows the most
recent firmware or a custom firmware to be pro-
grammed.
For general information of serial programming, please
refer to the In-Circuit Serial Programming (ICSP™)
Guide (DS30277). For specific details on programming
commands and operations for the PIC16F7X devices,
please refer to the latest version of the PIC16F7X
FLASH Program Memory Programming Specification
(DS30324).
FIGURE 12-13:
TYPICAL IN-CIRCUIT
SERIAL PROGRAMMING
CONNECTION
To Normal
Connections
External
Connector
Signals
+5V
0V
VPP
*
PIC16F7X
VDD
VSS
MCLR/VPP
CLK
RB6
Data I/O
RB7
***
VDD
To Normal
Connections
* Isolation devices (as required).
 2002 Microchip Technology Inc.
DS30325B-page 103