
HTG2190
Rev. 1.00
11
June 29, 2001
Mode
Program ROM Address
*15
*14 *13 *12
*11
*10
*9
*8
*7
*6
*5
*4
*3
*2
*1
*0
Initial reset
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
External or serial
input interrupt
0
0
0
0
0
0
0
0
0
0
0
0
0
1
0
0
Timer/event
counter 0 overflow
0
0
0
0
0
0
0
0
0
0
0
0
1
0
0
0
Timer/event
counter 1 overflow
0
0
0
0
0
0
0
0
0
0
0
0
1
1
0
0
Timer 2 overflow
0
0
0
0
0
0
0
0
0
0
0
1
0
0
0
0
Timer 3 overflow
0
0
0
0
0
0
0
0
0
0
0
1
0
1
0
0
Skip
PC+2
Loading PCL
*15
*14 *13 *12
*11
*10
*9
*8
@7
@6
@5
@4
@3
@2
@1
@0
Jump, call branch
BP.7 BP.6BP.5 #12
#11
#10
#9
#8
#7
#6
#5
#4
#3
#2
#1
#0
Return from
subroutine
S15
S14 S13 S12 S11 S10
S9
S8
S7
S6
S5
S4
S3
S2
S1
S0
Program ROM address
Note: *15~*0: Program ROM address
S15~S0: Stack register bits
@7~@0: PCL bits
BP.5~BP.7: Bit 5~7 of bank pointer (04H)
#12~#0: Instruction code bits
gram is in the program will always jump to the
appropriate interrupt service address in Bank
0. The original full 16 bit address will be stored
on the stack and restored when the relevant
RET/RETI instruction is executed, automati-
cally returning the program to the original
ROM bank. This eliminates the need for pro-
grammers to manage the BP when interrupts
occur.
Certain locations in Bank 0 of program mem-
ory are reserved for special usage:
ROM Bank 0 (BP5~BP7=000B)
The ROM bank 0 ranges from 0000H to
1FFFH.
Location 000H
This area is reserved for the initialization
program. After a chip reset, the program al-
ways begins execution at location 000H.
Location 004H
This area is reserved for the external inter-
rupt or serial input interrupt service routine.
If the INT input pin is activated, and the in-
terrupt is enabled and the stack is not full,
the program will jump to location 004H and
begins execution.
Location 008H/00CH
This area is reserved for the Timer/Event
Counter 0/1 interrupt service program. If a
timer interrupt results from a Timer/Event
Counter 0/1 overflow, and if the interrupt is en-
abled and the stack is not full, the program will
jump to location 008H/00CH and begins execu-
tion.
:
) :
3 :
6&
-
> &&
& 0
( 6 &
& 0
+ & 0
9 9 9 9 :
( 6 &
& 0
:
. &
& 0
4 &
& 0
:
) :
( & 0 $ $& ! &
3 :
Program memory