550
Digital Electronics
ALU
Shifter
Find One
D0
D1
D2
D3
D4
D5
D6
D7
TMPD
Data Registers
Address Registers
A0
A1
A2
A3
A4
A5
A6
A7
TMPA
Program Counter
PC
PC
Arithmetic
Unit
Main Control
CTRL
3Level
Instruction
Queue
Special Registers
A7
S
CC
Other Special
Registers
Interrupt
and
Exception
Control
Unit
Interrupt Control
Data Buffer
y
r
o
m
e
M e
c
a
f
r
e
t
n
I
Execution Unit
s
u
B
a
t
a
D
s
s
e
r
d
d
A s
u
B
l
o
r
t
n
o
C s
u
B
ipl_n
Clk
halti_n
reseti_n
reseto_n
halto_n
e
fc
addr
addrz
datao
datai
dataz
ctrlz
as_n
rw
uds_n
lds_n
dtack_n
br_n
bg_n
bgack_n
vpa_n
berr_n
vma
Figure 13.16 Block diagram of the 68000 microprocessor.