ht827a0 Holtek Semiconductor Inc., ht827a0 Datasheet - Page 9

• Manufacturer Part Number: ht827a0
• Description: 8-bit Microcontroller With Voice Rom
• Manufacturer: Holtek Semiconductor Inc.

Program memory - ROM
The program memory stores the to-be-executed
program instructions. It also includes data, ta-
ble and interrupt entries, addressed by the pro-
gram counter along with the table pointer.
The program memory size for HT827A0 is
8K´16.
Certain locations in the program memory are
reserved for special usage:
·
·
·
Initial reset
External interrupt
Sampling rate counter
overflow
Timer/event counter
overflow
Skip
Loading PCL
Jump, call branch
Return from subroutine
Note:
Location 000H
This area is reserved for program initializa-
tion. The program always begins execution at
location 000H each time the system is reset.
Location 004H
This area is reserved for an external interrupt
service program. The program begins execu-
tion at location 004H if the INT input pin is
activated, the interrupt is enabled and the
stack is not full.
Location 008H
This area is reserved for a voice sampling rate
counter interrupt service program. The pro-
gram begins execution at location 008H if a
timer interrupt results from a sampling rate
*12~*0: Bits of program counter
#12~#0: Bits of instruction code
Mode
S12 S11 S10 S9
*12 *11 *10
*12 *11 *10
#12 #11 #10
0
0
0
0
0
0
0
0
0
0
0
0
Program counter
*9
#9
*9
0
0
0
0
9
#8
S8
*8
*8
0
0
0
0
·
Program Counter
counter overflow, the interrupt is enabled and
the stack is not full.
Location 00CH
This area is reserved for a timer/event coun-
ter interrupt service program. The program
begins execution at location 00CH if an inter-
rupt results from a timer/event counter over-
flow, the interrupt is enabled and the stack is
not full.
@7
S7
*7
#7
S12~S0: Bits of stack register
@7~@0: Bits of PCL
0
0
0
0
PC+2
@6
S6
*6
#6
0
0
0
0
@5
#5
S5
*5
0
0
0
0
Program memory
@4
S4
*4
#4
0
0
0
0
@3
S3
*3
#3
0
0
1
1
@2
#2
S2
*2
0
1
0
1
March 15, 2000
HT827A0
@1
S1
*1
#1
0
0
0
0
@0
S0
*0
#0
0
0
0
0