PIC16LF145X Datasheet, PDF (12/38 Pages) Microchip Technology – PIC16(L)F145X Memory Programming Specification

PIC16(L)F145X
4.2.1
LEGACY ICSP PINOUT
PROGRAMMING
The legacy ICSP pinout is for use with designs based
on previous PIC18F1XK50 20-pin parts. This allows
the programming through the same pinout layout. If
LVP = 1, the PIC^® device can be programmed through
the recommended pins or the legacy pins (refer to
Table 4-1).
When LVP is set, entry into the Low-Voltage ICSP
Program/Verify mode, as well as the programming
method, is the same as discussed in Section 4.2
“Low-Voltage Programming (LVP) Mode”. However,
both the legacy and recommended ICSPDAT are
monitored while clocking ICSPCLK. Whichever
ICSPDAT first receives the 32-bit key sequence will be
used for programming with its corresponding
ICSPCLK.
Note:
The VIH voltage levels on port pins
RA0/ICSPDAT/D+ and RA1/ICSPCLK/D-
must be limited to 3.3V maximum, due to
USB circuitry. The device must not be
attached to a USB host and the USB mod-
ule must be disabled. Refer to Figure 4-1,
Figure 4-2 and Figure 4-3.
TABLE 4-1: LEGACY PIN DESCRIPTIONS DURING PROGRAMMING
Pin Name
Function
During Programming
Pin Type
Pin Description
RA1
ICSPCLK
I
Clock Input – Schmitt Trigger Input
RA0
ICSPDAT
I
Data Input – Schmitt Trigger Input
MCLR/VPP/RA3
Program/Verify mode
P⁽¹⁾
Program Mode Select/Programming Power Supply
VDD
VDD
P
Power Supply
VSS
VSS
P
Ground
Legend:
Note 1:
I = Input, O = Output, P = Power
The programming high voltage is internally generated. To activate the Program/Verify mode, high voltage needs to be
applied to MCLR input. Since the MCLR is used for a level source, MCLR does not draw any significant current.
FIGURE 4-1:
IN-CIRCUIT PROGRAMMING (ICSP) RECOMMENDED METHOD
Application
Programmer
VPP
+5V
VDD
MCLR/VPP/RA3
VSS
VSS
RC0/ICSPDAT
RC1/ICSPCLK
ICSPDAT
ICSPCLK
DS41620C-page 12
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