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FLASH PROGRAM MEMORY (Cont’d)
4.5 ICP (In-Circuit Programming)
To perform ICP the microcontroller must be
switched to ICC (In-Circuit Communication) mode
by an external controller or programming tool.
Depending on the ICP code downloaded in RAM,
Flash memory programming can be fully custom-
ized (number of bytes to program, program loca-
tions, or selection serial communication interface
for downloading).
When using an STMicroelectronics or third-party
programming tool that supports ICP and the spe-
cific microcontroller device, the user needs only to
implement the ICP hardware interface on the ap-
plication board (see Figure 13). For more details
on the pin locations, refer to the device pinout de-
scription.
ICP needs six pins to be connected to the pro-
gramming tool. These pins are:
– RESET: device reset
–VSS: device power supply ground
– ICCCLK: ICC output serial clock pin
– ICCDATA: ICC input serial data pin
– ICCSEL/VPP: programming voltage
–VDD: application board power supply
CAUTIONS:
1. If RESET, ICCCLK or ICCDATA pins are used
for other purposes in the application, a serial resis-
tor has to be implemented to avoid a conflict in
case one of the other devices forces the signal lev-
el. If these pins are used as outputs in the applica-
tion, the serial resistors are not necessary. As
soon as the external controller is plugged to the
board, even if an ICC session is not in progress,
the ICCCLK and ICCDATA pins are not available
for the application.
2. The use of Pin 7 of the ICC connector depends
on the Programming Tool architecture. Please re-
fer to the documentation of the tool. This pin must
be connected when using ST Programming Tools
(it is used to monitor the application power supply).
Note: To develop a custom programming tool, re-
fer to the ST7 Flash Programming and ICC Refer-
ence Manual which gives full details on the ICC
protocol hardware and software.
Figure 13. Typical ICP Interface
ICC CONNECTOR
IC
C
D
AT
A
IC
C
L
K
R
ESE
T
VD
D
HE10 CONNECTOR TYPE
>4.7k
APPLICATION
POWER SUPPLY
OPTIONAL (SEE CAUTION 1)
1
2
4
6
8
10
97
5
3
PROGRAMMING TOOL
ICC CONNECTOR
APPLICATION BOARD
ICC Cable
OPTIONAL
(SEE CAUTION 2)
10k
VSS
IC
C
SEL
/VPP
ST7
1