HT45FM03B Datasheet, PDF (15/83 Pages) Holtek Semiconductor Inc – Brushless DC Motor Flash Type 8-Bit MCU

HT45FM03B
Data Memory
The Data Memory is a volatile area of 8-bit wide RAM
internal memory and is the location where temporary in-
formation is stored. Divided into two sections, the first of
these is an area of RAM where special function registers
are located. These registers have fixed locations and
are necessary for correct operation of the device. Many
of these registers can be read from and written to di-
rectly under program control, however, some remain
protected from user manipulation. The second area of
Data Memory is reserved for general purpose use. All
locations within this area are read and write accessible
under program control.
Structure
The two sections of Data Memory, the Special Purpose
and General Purpose Data Memory are located at con-
secutive locations. All are implemented in RAM and are
8 bits wide. The start address of the Data Memory is the
address ²00H².
00H
S p e c ia l P u r p o s e
D a ta M e m o ry
3FH
40H
G e n e ra l P u rp o s e
D a ta M e m o ry
FFH
Data Memory Structure
Note:
Most of the RAM Data Memory bits can be di-
rectly manipulated using the ²SET [m].i² and
²CLR [m].i² instructions with the exception of a
few dedicated bits. The RAM Data Memory can
also be accessed through the Memory Pointer
registers MP0 and MP1.
General Purpose Data Memory
All microcontroller programs require an area of
read/write memory where temporary data can be stored
and retrieved for use later. It is this area of RAM memory
that is known as General Purpose Data Memory. This
area of Data Memory is fully accessible by the user pro-
gram for both read and write operations. By using the
²SET [m].i² and ²CLR [m].i² instructions individual bits
can be set or reset under program control giving the
user a large range of flexibility for bit manipulation in the
Data Memory.
00H
In d ir e c t A d d r e s s in g R e g is te r 0
01H
M P0
02H
In d ir e c t A d d r e s s in g R e g is te r 1
03H
M P1
04H
05H
ACC
06H
PCL
07H
TB LP
08H
TB LH
09H
W D TS
0A H
STATU S
0B H
IN T C 0
0C H
0D H
TM R 0
0E H
TM R 0C
0FH
TM R 1H
10H
TM R 1L
11H
TM R 1C
12H
PA
13H
PAC
14H
PB
15H
PBC
16H
PC
17H
PCC
18H
PD
19H
PDC
1A H
P W M 0H
1B H
P W M 0L
1C H
PW M C0
1D H
PW M C1
1E H
IN T C 1
1FH
M F IC
20H
ADRL
21H
ADRH
22H
ADCR
23H
ACSR
24H
CM PC
25H
M IS C
26H
O PAC
27H
D BTC
28H
29H
2A H
P W M 1H
2B H
P W M 1L
2C H
P W M 2H
2D H
P W M 2L
2E H
PCPW M C
2FH
PCPW M D
30H
LV D C TL
31H
PW M C2
S p e c ia l P u r p o s e
D a ta M e m o ry
: U n u s e d re a d a s "0 0 "
Special Purpose RAM Data Memory
Rev. 1.00
15
December 16, 2009