ST SPC58XXADPT176S, User Manual, Page: 22 / 28

Figure 7. Clock and reset circuitry
J22
STRIP2PMD-2MM-O
1 2
GND
GND
Vcc
U3A
74LVC125AMTR
2 3
7
14 1
GND
Vcc
U3B
74LVC125AMTR
5 6
7
14 4
GND
Vcc
U3C
74LVC125AMTR
9 8
7
14 10
GND
GND
VDD_HV_IO_MAIN
VDD_HV_IO_MAIN
GND
VCC
U4
74V1G08STR
1
2
4
5
3
1
2
P1
SMA-FEM-180
VDD_HV_IO_MAIN
VDD_HV_IO_MAIN
EXTAL(pg3)
J21
STRIP3PMD-2MM
1
2
3
XTAL(pg3)
RST-SW (pg6)
EVB-EXTAL
ESR0 (pg3,5)
EVB-EXTAL
PORST(pg3,5)
J23
STRIP3PMD-2MM
1
2
3
U2
8MHz
EN
1
GND
2
OUT
3
+Vs
4
SW1
Pushbutton NO B6110-0
R7 0R
R5
DNM
R6
DNM
R8 100R
R9 10K
R13
4K7
R11
4K7
R10 560R
R14
4K7
R12 560R
D1 Yellow D4
Red
C58 100nF
Reset Circuit
External Oscillator External Clock Input
GND
Note - External 3.3V
regulator MUST be
enabled when using
oscillator module
SMA style
Connector
EVB-EXTAL
OSC-MOD
GND
EXTAL-SMA
3.3V_SR
J24
STRIP3PMD-2MM
1
2
3
Note - Internal
Pull-Up on Pin 1
EXTAL
Loop Controlled Pierce
Oscillator Circuit
VSS_OSC
XTAL
GND
EVB-EXTAL
Connect XTAL jumper to GND when driving EXTAL from
Oscilaltor Module or External Source (PLL Bypass
Mode)
(MCU Crystal Output)
(MCU Crystal Input)
REMOVE XTAL jumper when driving EXTAL from
Oscillator Module or External Source (PLL Enabled)
GND
GND
MCU RESET LED
J25
STRIP2PMD-2MM
1 2
J26
STRIP2PMD-2MM
1 2 PORST
ESR0
J27
STRIP2PMD-2MM
1 2
VDD_HV_IO_MAIN
USR RESET LED VDD_HV_IO_MAIN
RST-MCU
GND
GND
RST-SW
Reset-In
Disable
Y1
40MHz
1
2
UM2723
-
Rev 1
page 22/28
UM2723
Schematic