MC9S08QG8 Datasheet, PDF (25/300 Pages) Freescale Semiconductor, Inc – 8-BIT HCS08 Central Processor Unit

Chapter 2 External Signal Description
2.2 Recommended System Connections
Figure 2-3 shows pin connections that are common to almost all MC9S08QG8/4 application systems.
SYSTEM
POWER
+
3V
V_DD
C_{BLK +}
10 µF
MC9S08QG8/4
V_DD
C_BY
0.1 µF
V_SS
PORT
A
NOTE 1
R_F
R_S
C1
X1
C2
XTAL
NOTE 2
EXTAL
NOTE 2
BACKGROUND HEADER
V_DD
ASYNCHRONOUS
INTERRUPT
INPUT
V_DD
4.7 kΩ–10 kΩ
OPTIONAL
MANUAL
RESET
0.1 µF
BKGD
RESET/IRQ
PORT
B
PTA0/KBIP0/TPMCH0/ADP0/ACMP+
PTA1/KBIP1/ADP1/ACMP–
PTA2/KBIP2/SDA/ADP2
PTA3/KBIP3/SCL/ADP3
PTA4/ACMPO/BKGD/MS
PTA5/IRQ/TCLK/RESET
I/O AND
PERIPHERAL
INTERFACE TO
APPLICATION
SYSTEM
PTB0/KBIP4/RxD/ADP4
PTB1/KBIP5/TxD/ADP5
PTB2/KBIP6/SPSCK/ADP6
PTB3/KBIP7/MOSI/ADP7
PTB4/MISO
PTB5/TPMCH1/SS
PTB6/SDA/XTAL
PTB7/SCL/EXTAL
NOTES:
1. Not required if using the internal clock option.
2. XTAL is the same pin as PTB6; EXTAL the same pin as PTB7.
3. RESET pin can only be used to reset into user mode, you can not enter BDM using RESET pin. BDM can
be entered by holding MS low during POR or writing a 1 to BDFR in SBDFR with MS low after issuing BDM
command.
4. IRQ feature has optional internal pullup device.
5. RC filter on RESET/IRQ pin recommended for noisy environments.
Figure 2-3. Basic System Connections
2.2.1 Power
V_DD and V_SS are the primary power supply pins for the MCU. This voltage source supplies power to all
I/O buffer circuitry, ACMP and ADC modules, and to an internal voltage regulator. The internal voltage
regulator provides regulated lower-voltage source to the CPU and other internal circuitry of the MCU.
MC9S08QG8 and MC9S08QG4 Data Sheet, Rev. 1.01
Freescale Semiconductor
25