PIC16LC925T-I/CL View Datasheet(PDF) - Microchip Technology
Part Name
Description
Manufacturer
PIC16LC925T-I/CL Datasheet PDF : 182 Pages
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PIC16C925/926
FIGURE 12-14: 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>)
Processor in
SLEEP
Interrupt Latency
(Note 2)
INSTRUCTION FLOW
PC
Instruction
Fetched
Instruction
Executed
PC
Inst(PC) = SLEEP
Inst(PC - 1)
PC+1
Inst(PC + 1)
SLEEP
PC+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 = 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.
12.9 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.
Note: Microchip does not recommend code pro-
tecting windowed devices.
12.10 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 four Least Significant bits of the
ID location are used.
12.11 In-Circuit Serial Programming
PIC16CXXX 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. 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 firm-
ware to be programmed.
The device is placed into a Program/Verify mode by
holding the RB6 and RB7 pins low, while raising the
MCLR (VPP) pin from VIL to VIHH (see programming
specification). RB6 becomes the programming clock
and RB7 becomes the programming data. Both RB6
and RB7 are Schmitt Trigger inputs in this mode.
After RESET, to place the device into Program/Verify
mode, the program counter (PC) is at location 00h. A
6-bit command is then supplied to the device. Depend-
ing on the command, 14-bits of program data are then
supplied to or from the device, depending if the com-
mand was a load or a read. For complete details of
serial programming, please refer to the PIC16C6X/7X
Programming Specifications (Literature #DS30228).
FIGURE 12-15:
TYPICAL IN-CIRCUIT
SERIAL PROGRAMMING
CONNECTION
External
Connector
Signals
+5V
0V
VPP
CLK
Data I/O
To Normal
Connections
PIC16CXXX
VDD
VSS
MCLR/VPP
RB6
RB7
To Normal
Connections
VDD
DS39544A-page 112
Preliminary
2001 Microchip Technology Inc.
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