
General Description
Block Diagram
MC68HC705C8A — Rev. 3
Technical Data
MOTOROLA
General Description
Figure 1-2. MC68HC705C8A Block Diagram
INTERNAL
PROCESSOR
CLOCK
TCAP
÷ 2
ACCUMULATOR
INDEX REGISTER
OSC1
OSC2
OSCILLATOR
IRQ
RESET
COP WATCHDOG
CPU
M68HC05 CPU
ARITHMETIC
V
DD
V
SS
CPU REGISTERS
CONTROL
POR
T
A
DA
TA
DIR
E
C
TIO
N
A
PA0
PA1
PA2
PA3
PA4
PA5
PA6
PA7
POWER
OPTION
EPROM/OTPROM — 7744 BYTES
1
0
C
Z
N
I
H
1
16-BIT
CAPTURE/COMPARE
PO
R
T
B
D
A
TA
DI
RE
CTI
O
N
B
PB0
*
PB1
*
PB2
*
PB3
*
PB4
*
PB5
*
PB6
*
PB7
*
POR
T
C
DA
TA
DIR
E
C
TIO
N
C
PC0
PC1
PC2
PC3
PC4
PC5
PC6
PC7
TIMER SYSTEM
BAUD RATE
GENERATOR
PD7
RDI (PD0)
TDO (PD1)
MISO (PD2)
MOSI (PD3)
SCK (PD4)
SS (PD5)
SCI
SPI
TCMP
RAM — 176 BYTES
REGISTER
BOOT ROM — 240 BYTES
(144 BYTES CONFIGURABLE)
PROGRAM REGISTER
EPROM PROGRAMMING
VPP
AND
CLOCK MONITOR
POR
T
D
LOGIC UNIT
(304 BYTES MAXIMUM)
CONTROL
PROGRAM COUNTER
STACK POINTER
CONDITION CODE REGISTER
* Port B pins also function as external interrupts.
PC7 has a high current sink and source capability.
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Freescale Semiconductor, Inc.
For More Information On This Product,
Go to: www.freescale.com
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