ST7263B Datasheet, PDF (6/132 Pages) STMicroelectronics – LOW SPEED USB 8-BIT MCU FAMILY WITH FLASH/ROM, UP TO 512 BYTES RAM, 8-BIT ADC, WDG, TIMER, SCI & I²C

ST7263B
PIN DESCRIPTION (Cont’d)
RESET (see Note 1): Bidirectional. This active low
signal forces the initialization of the MCU. This
event is the top priority non maskable interrupt.
This pin is switched low when the Watchdog is trig-
gered or the V_DD is low. It can be used to reset ex-
ternal peripherals.
OSCIN/OSCOUT: Input/Output Oscillator pin.
These pins connect a parallel-resonant crystal, or
an external source, to the on-chip oscillator.
V_DD/V_SS (see Note 2): Main Power Supply and
Ground voltages.
V_DDA/V_SSA (see Note 2): Power Supply and
Ground voltages for analog peripherals.
Table 2. Device Pin Description
Alternate Functions: Several pins of the I/O ports
assume software programmable alternate func-
tions as shown in the pin description.
Note 1: Adding two 100 nF decoupling capacitors
on the Reset pin (respectively connected to V_DD
and V_SS) will significantly improve product electro-
magnetic susceptibility performance.
Note 2: To enhance the reliability of operation, it is
recommended that V_DDA and V_DD be connected to-
gether on the application board. This also applies
to V_SSA and V_SS.
Pin n°
Pin Name
Level
Port / Control
Input
Output
Main
Function
(after reset)
Alternate Function
1 1 V_DD
2 2 OSCOUT
3 3 OSCIN
4 4 V_SS
5 5 PC2/USBOE
6 6 PC1/TDO
7 7 PC0/RDI
8 8 RESET
-- 9 NC
9 10 PB7/AIN7/IT8
10 11 PB6/AIN6/IT7
11 12 V_PP/TEST
12 13 PB5/AIN5/IT6
13 14 PB4/AIN4/IT5
14 15 PB3/AIN3
15 16 PB2/AIN2
16 17 PB1/AIN1
17 18 PB0/AIN0
18 19 PA7/OCMP2/IT4
19 20 PA6/OCMP1/IT3
20 21 PA5/ICAP2/IT2
21 22 PA4/ICAP1/IT1
S
Power supply voltage (4V - 5.5V)
O
Oscillator output
I
Oscillator input
S
Digital ground
I/O
C_T
X
I/O
C_T
X
I/O
C_T
X
I/O
X
X Port C2
X Port C1
X Port C0
X
Reset
USB Output Enable
SCI Transmit Data Output*
SCI Receive Data Input*
--
Not connected
I/O C_T 10mA X
I/O C_T 10mA X
S
XX
XX
X Port B7
ADC analog input 7
X Port B6
ADC analog input 6
Programming supply
I/O C_T 10mA X
XX
I/O C_T 10mA X
XX
I/O C_T 10mA X
X
I/O C_T 10mA X
X
I/O C_T 10mA X
X
I/O C_T 10mA X
X
I/O
C_T
XX
I/O
C_T
XX
I/O
C_T
XX
I/O
C_T
XX
X Port B5
X Port B4
X Port B3
X Port B2
X Port B1
X Port B0
X Port A7
X Port A6
X Port A5
X Port A4
ADC analog input 5
ADC analog input 4
ADC analog input 3
ADC analog input 2
ADC analog input 1
ADC Analog Input 0
Timer Output Compare 2
Timer Output Compare 1
Timer Input Capture 2
Timer Input Capture 1
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