MC68HC08JB1 Datasheet, PDF (27/216 Pages) Motorola, Inc – Microcontrollers

1.5 Pin Assignments
V_SS
1
OSC1 2
OSC2 3
V_REG
4
V_DD
5
PTD0/1 6
PTE1/TCH0 7
PTE3/D+ 8
PTE4/D– 9
PTC0 10
20 ^RST
19 ^PTA0/KBA0
18 ^PTA1/KBA1
17 ^PTA2/KBA2
16 ^PTA3/KBA3
15 ^PTA4/KBA4
14 ^PTA5/KBA5
13 ^PTA6/KBA6
12 ^PTA7/KBA7
11 ^IRQ
Figure 1-2. 20-pin PDIP/SOIC Pin Assignments
NOTE: The PTD0 and PTD1 internal pads are bonded together to PTD0/1 pin.
1.5.1 Power Supply Pins (V_DD, V_SS)
V_DD and V_SS are the power supply and ground pins. The MCU operates
from a single power supply.
Fast signal transitions on MCU pins place high, short-duration current
demands on the power supply. To prevent noise problems, take special
care to provide power supply bypassing at the MCU as Figure 1-3
shows. Place the bypass capacitors as close to the MCU power pins as
possible. Use high-frequency-response ceramic capacitors for C_BYPASS.
C_BULK are optional bulk current bypass capacitors for use in applications
that require the port pins to source high current levels.
MC68HC08JB1 — Rev. 2.1
Freescale Semiconductor
Technical Data
27