ht82a523r Holtek Semiconductor Inc., ht82a523r Datasheet - Page 7

• Manufacturer Part Number: ht82a523r
• Description: Ht82a523r -- Usb 2.0 Full Speed 8-bit Otp Mcu
• Manufacturer: Holtek Semiconductor Inc.

Program Memory - EPROM
The program memory (EPROM) is used to store the pro-
gram instructions which are to be executed. It also con-
tains data, table, and interrupt entries, and is organized
into 4096 15 bits which are addressed by the Program
Counter and table pointer.
Certain locations in the ROM are reserved for special
usage:
Note: *11~*0: Table location bits
Rev. 1.30
TABRDC [m]
TABRDL [m]
Location 000H
Location 000H is reserved for program initialization.
After a chip reset, the program always begins execu-
tion at this location.
Location 004H
Location 004H is reserved for the external interrupt
service program. If the INT input pin is activated, and
the interrupt is enabled, and the stack is not full, the
program begins execution at location 004H.
Location 008H
Location 008H is reserved for the Timer/Event Coun-
ter 0 interrupt service program. If a timer interrupt re-
sults from a Timer/Event Counter 0 overflow, and if the
interrupt is enabled and the stack is not full, the pro-
gram begins execution at location 008H.
Location 00CH
Location 00CH is reserved for the Timer/Event Coun-
ter 1 interrupt service program. If a timer interrupt re-
sults from a Timer/Event Counter 1 overflow, and if the
interrupt is enabled and the stack is not full, the pro-
gram begins execution at location 00CH.
Location 010H
Location 010H is reserved for the USB interrupt ser-
vice program. If the USB interrupt is activated, the in-
terrupt is enabled and the stack is not full, the program
begins execution at location 010H.
Location 014H
Location 014H is reserved for 8 bits data have been
received or transmitted successful from serial inter-
face , and the related interrupts are enabled, and the
stack is not full, the program begins execution at loca-
tion 014H.
Location 018H
Location 018H is reserved for 8 bits data have been
received or transmitted successful from serial inter-
face 2, and the related interrupts are enabled, and the
stack is not full, the program begins execution at loca-
tion 018H.
Instruction
@7~@0: Table pointer bits
P11
*11
1
P10
*10
1
P9
*9
1
P8
*8
1
Table Location
@7
@7
*7
7
Table Location
P11~P8: Current program counter bits
@6
@6
*6
Table location
Any location in the program memory can be used as a
look-up tables. There are three methods to read the
ROM data using two table read instructions
the lower-order byte to the specified data memory,
and the higher-order byte to TBLH (08H).
The three methods are shown as follows:
TABRDC and TABRDL , transfer the contents of
The instruction TABRDC [m] (the current page,
one page=256 words), where the table location is
defined by TBLP (07H) in the current page. The
configuration option, TBHP, is disabled (default).
The instructions TABRDC [m] , where the table lo-
cation is defined by registers TBLP (07H) and
TBHP (01FH). The configuration option, TBHP, is
enabled.
The instruction TABRDL [m] , where the table lo-
cations is defined by registers TBLP (07H) in the
last page (0F00H~0FFFH).
@5
@5
*5
@4
@4
*4
Program Memory
@3
@3
*3
@2
@2
*2
HT82A523R
@1
@1
May 13, 2008
*1
@0
@0
*0