PIC17CXX Datasheet, PDF (4/16 Pages) Microchip Technology – EPROM Memory Programming Specification

PIC17CXX
3.0 PROGRAMMING SPECIFICATIONS
FIGURE 3-1: PROGRAMMING ROUTINE FLOWCHART
Reset
RA2 = 0
RA3 = 0
RA4 = 1
MCLR = 1
B port = 0xE1
(hold for 10 Tcy)
Present address on ports
RB, RC hold Tcy
after RA1 changes to 1
No
RA1
=0
Yes
No
RA1
=1
Yes
Read MSB of data
from port-B.
Read LSB of data
from port-C.
Enable RA0 to end
prog cycle
Program 16 bit
data
No
RA1
=0
Yes
No
RA1
=1
Yes
No
RA1
=0
Yes
B & C ports not
driven by part
If programming is desired,
force port B = MSB of data
force port C = LSB of data
(hold 10Tcyc after
RA0 is raised)
Stop driving address
on port
No
RA1
=0
Yes
No
RA1
=1
Yes
B port = MSB of Data
C port = LSB of Data
No
RA0 = 0
Yes
RA1 ^Yes
=0
Yes
RA0= 1
No
No
Yes
No _RA1
=1
Yes
RA0= 1
No
RA1
No
=1
Yes
Increment
Address
B port = xxx
- B port is forced by the part
B port = xxx
- B port is tri-state, should be forced by user
Min RA1 high or low = 10 Tcy
DS30139I-page 4
© 1996 Microchip Technology Inc.