Datasheet

MCP2502X/5X
DS21664D-page 50 © 2007 Microchip Technology Inc.
8.7 In-Circuit Serial Programming
The MCP2502X/5X can be serially programmed 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 device
just before shipping the product, also allowing the
most recent firmware (or a custom firmware) to be
programmed.
The device is placed into a program/verify mode by
holding the GP4 and GP5 pins low while raising GP7
(V
PP) pin from VIL to VIH (see the MCP2502X/5X
programming specification, “MCP250XX In-Circuit
Serial Programming™ (ICSP)”, DS20072, for more
information). GP4 becomes the programming data and
GP5 becomes the programming clock. Both GP4 and
GP5 are Schmitt Trigger inputs in this mode. The signal
definitions are summarized in Table 8-1
TABLE 8-1: IN-CIRCUIT SERIAL
PROGRAMMING PIN
FUNCTIONS
Pin Name
Pin
Number
Programming Mode
Function
V
SS 7 Ground
GP4 5 Data
GP5 6 Clock
GP7 11 V
PP
VDD 14 Power