HT46R47
Certain locations in the program memory are
reserved for special usage:
·
Location 000H
0 0 0 H
0 0 4 H
0 0 8 H
0 0 C H
D e v ic e In itia liz a tio n P r o g r a m
E x te r n a l In te r r u p t S u b r o u tin e
T im e r /E v e n t C o u n te r In te r r u p t S u b r o u tin e
A /D
C o n v e r te r In te r r u p t S u b r o u tin e
P ro g ra m
M e m o ry
n 0 0 H
n F F H
L o o k - u p T a b le ( 2 5 6 w o r d s )
This area is reserved for program initializa-
tion. After chip reset, the program always be-
gins execution at location 000H.
·
Location 004H
This area is reserved for the external inter-
rupt service program. If the INT input pin is
activated, the interrupt is enabled and the
stack is not full, the program begins execution
at location 004H.
·
Location 008H
This area is reserved for the timer/event coun-
ter interrupt service program. If a timer inter-
rupt results from a timer/event counter
overflow, and if the interrupt is enabled and the
stack is not full, the program begins execution
at location 008H.
·
Location 00CH
7 0 0 H
7 F F H
L o o k - u p T a b le ( 2 5 6 w o r d s )
1 4 b its
N o te : n ra n g e s fro m
0 to 7
Program memory
·
Table location
This area is reserved for the A/D converter in-
terrupt service program. If an A/D converter
interrupt results from an end of A/D conver-
sion, and if the interrupt is enabled and the
stack is not full, the program begins execution
at location 00CH.
Any location in the PROM space can be used
as look-up tables. The instructions "TABRDC
[m]" (the current page, 1 page=256 words)
and "TABRDL [m]" (the last page) transfer
the contents of the lower-order byte to the
specified data memory, and the higher-order
byte to TBLH (08H). Only the destination of
the lo w e r -or der by te i n th e t abl e i s
Program Counter
Mode
Initial Reset
External Interrupt
Timer/Event Counter Overflow
A/D Converter Interrupt
Skip
Loading PCL
Jump, Call Branch
Return from Subroutine
*10
0
0
0
0
*10
#10
S10
*9
0
0
0
0
*9
#9
S9
*8
0
0
0
0
*8
#8
S8
*7
0
0
0
0
@7
#7
S7
*6
0
0
0
0
@6
#6
S6
*5
0
0
0
0
PC+2
@5
#5
S5
*4
0
0
0
0
@4
#4
S4
*3
0
0
1
1
@3
#3
S3
*2
0
1
0
1
@2
#2
S2
*1
0
0
0
0
@1
#1
S1
*0
0
0
0
0
@0
#0
S0
Program counter
Note: *10~*0: Program counter bits
#10~#0: Instruction code bits
Rev. 1.40
7
S10~S0: Stack register bits
@7~@0: PCL bits
July 18, 2001
HOLTEK [ HOLTEK SEMICONDUCTOR INC ]
