mc9s08gt16a Freescale Semiconductor, Inc, mc9s08gt16a Datasheet - Page 30

• Manufacturer Part Number: mc9s08gt16a
• Description: Hcs08 Microcontrollers 8-bit Microcontroller Family
• Manufacturer: Freescale Semiconductor, Inc

Pins and Connections
2.3.5
IRQ is a dedicated pin with both pullup and pulldown devices built in. This pin has no output capabilities.
After a system reset, the IRQ pin is disabled and must be enabled before use. See
External Interrupt Request
For EMC-sensitive applications, an external RC filter is recommended on the IRQ pin. See
an example.
2.3.6
The remaining 36 pins are shared among general-purpose I/O and on-chip peripheral functions such as
timers and serial I/O systems. (Three of these pins are not bonded out on the 44-pin package, five are not
bonded out on the 42-pin package, and 15 are not bonded out on the 32-pin package.) Immediately after
reset, all 36 of these pins are configured as high-impedance general-purpose inputs with internal pullup
devices disabled.
For information about controlling these pins as general-purpose I/O pins, see
Input/Output.” For information about how and when on-chip peripheral systems use these pins, refer to the
appropriate section from
30
1
PTA7–PTA0
PTB7–PTB0
PTC7–PTC4
PTC3–PTC2
PTC1–PTC0
PTD4–PTD3
PTD2–PTD0
PTE5
PTE4
PTE3
PTE2
PTE1–PTE0
PTG3
PTG2–PTG1
PTG0
See this section for information about modules that share these pins.
Port Pins
IRQ — External Interrupt Request Pin
General-Purpose I/O and Peripheral Ports
To avoid extra current drain from floating input pins, the reset initialization
routine in the application program should either enable on-chip pullup
devices or change the direction of unused pins to outputs so the pins do not
float.
KBIP7–KBIP0
ADP7–ADP0
SCL–SDA
RxD2–TxD2
TPM2CH1–TPM2CH0, TPM2CLK
TPM1CH2–TPM1CH0, TPM1CLK
SPSCK
MISO
MOSI
SS
RxD1–TxD1
EXTAL–XTAL
BKGD/MS
Alternate Function
Table
Pin” for more details.
2-1.
MC9S08GT16A/GT8A Data Sheet, Rev. 1
Table 2-1. Pin Sharing References
NOTE
Chapter 7, “Keyboard Interrupt (S08KBIV1)”
Chapter 14, “Analog-to-Digital Converter (S08ATDV3)”
Chapter 13, “Inter-Integrated Circuit (S08IICV1)”
Chapter 11, “Serial Communications Interface (S08SCIV1)”
Chapter 10, “Timer/PWM (S08TPMV2)”
Chapter 10, “Timer/PWM (S08TPMV2)”
Chapter 12, “Serial Peripheral Interface (S08SPIV3)”
Chapter 11, “Serial Communications Interface (S08SCIV1)”
Chapter 9, “Internal Clock Generator (S08ICGV4)”
Chapter 15, “Development Support”
Reference
Chapter 6, “Parallel
1
Section 5.4.2, “IRQ —
Freescale Semiconductor
Figure 2-5
for