AN1212 Freescale Semiconductor / Motorola, AN1212 Datasheet - Page 6

• Manufacturer Part Number: AN1212
• Description: J1850 Multiplex Bus Communication Using the MC68HC705C8 and the SC371016 J1850 Communications Interface (JCI)
• Manufacturer: Freescale Semiconductor / Motorola

AN1212/D
Memory
6
PB0
PB1
PB2
PB3
PB4
PB5
PB6
PB7
PA0
PA1
PA2
PA3
PA4
PA5
PA6
PA7
TCAP
TCMP
SYSTEM
TIMER
J1850 Multiplex Bus Communication Using the MC68HC705C8
BOOTSTRAP
USER PROM
(7600 X 8)
7744 X 8
and the SC371016 J1850 Communications Interface (JCI)
240 X 8
The MC68HC705C8 MCU contains 7600 bytes of EPROM (including user-
defined reset and interrupt vectors), 223 bytes of bootstrap ROM, and 176
bytes of static RAM. The user can also access up to an additional 144 bytes of
user EPROM or 128 bytes of RAM, by programming the RAM1:0 bits of the
OPTION register (address $1FDF) on the MC68HC705C8, or by mask option
selection on the MC68HC05C8. All ROM and RAM is memory mapped,
allowing the user to directly read from (ROM, RAM) or write to (RAM) any
memory location. The MC68HC705C8 OPTION register contains a security bit
ROM
Freescale Semiconductor, Inc.
PROCESSOR
INTERNAL
Figure 4. MC68HC705C8 Block Diagram
For More Information On This Product,
CLOCK
8
8
5
8
8
8
ACCUMULATOR
CONDITION
REGISTER
REGISTER
PROGRAM
PROGRAM
COUNTER
COUNTER
POINTER
STACK
INDEX
CODE
HIGH
LOW
OSC1
OSCILLATOR
DIVIDE BY 2
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PCH
AND
PCL
CC
SP
A
X
PROGRAM
REGISTER
OSC2
CPU
CONTROL
CPU
ALU
COP CLOCK
MONITOR
STATIC RAM
(304 X 8)
176 X 8
GENERATOR
BAUD-RATE
PORT D
SCI
SPI
RESET
IRQ
PC0
PC1
PC2
PC3
PC4
PC5
PC6
PC7
PD7
RDI (PD0)
TD0 (PD1)
MISO (PD2)
MOSI (PD3)
SCK (PD4)
SS (PD5)
INTERNAL
PROCESSOR
CLOCK
MOTOROLA