ST72F321J ST Microelectronics, ST72F321J Datasheet - Page 17

• Manufacturer Part Number: ST72F321J
• Description: 8-BIT MCU
• Manufacturer: ST Microelectronics

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DataSheet
FLASH PROGRAM MEMORY (Cont’d)
4.4 ICC Interface
ICC needs a minimum of 4 and up to 6 pins to be
connected to the programming tool (see
These pins are:
Figure 5. Typical ICC Interface
Notes:
1. If the ICCCLK or ICCDATA pins are only used
as outputs in the application, no signal isolation is
necessary. As soon as the Programming Tool 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. If they are used as
inputs by the application, isolation such as a serial
resistor has to implemented in case another de-
vice forces the signal. Refer to the Programming
Tool documentation for recommended resistor val-
ues.
2. During the ICC session, the programming tool
must control the RESET pin. This can lead to con-
flicts between the programming tool and the appli-
cation reset circuit if it drives more than 5mA at
high level (push pull output or pull-up resistor<1K).
A schottky diode can be used to isolate the appli-
cation RESET circuit in this case. When using a
classical RC network with R>1K or a reset man-
– RESET: device reset
– V
APPLICATION
POWER SUPPLY
4
SS
U
.com
: device power supply ground
OPTIONAL
(See Note 3)
PROGRAMMING TOOL
C
L2
OPTIONAL
(See Note 4)
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C
ST7
Figure
L1
5).
10k
10
ICC CONNECTOR
9
agement IC with open drain output and pull-up re-
sistor>1K, no additional components are needed.
In all cases the user must ensure that no external
reset is generated by the application during the
ICC session.
3. The use of Pin 7 of the ICC connector depends
on the Programming Tool architecture. This pin
must be connected when using most ST Program-
ming Tools (it is used to monitor the application
power supply). Please refer to the Programming
Tool manual.
4. Pin 9 has to be connected to the OSC1 or OS-
CIN pin of the ST7 when the clock is not available
in the application or if the selected clock option is
not programmed in the option byte. ST7 devices
with multi-oscillator capability need to have OSC2
grounded in this case.
7
8
– ICCCLK: ICC output serial clock pin
– ICCDATA: ICC input/output serial data pin
– ICCSEL/V
– OSC1(or OSCIN): main clock input for exter-
– V
nal source (optional)
al, see
5
6
DD
ICC Cable
: application board power supply (option-
4
3
Figure
1
2
PP
HE10 CONNECTOR TYPE
: programming voltage
5, Note 3)
ICC CONNECTOR
APPLICATION BOARD
APPLICATION
See Note 2
APPLICATION
RESET SOURCE
See Note 1
I/O
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