ST62T42B ST Microelectronics, ST62T42B Datasheet - Page 10

• Manufacturer Part Number: ST62T42B
• Description: 8-BIT OTP/EPROM MCU WITH LCD DRIVER / EEPROM AND A/D CONVERTER
• Manufacturer: ST Microelectronics

ST62T42B/E42B
MEMORY MAP (Cont’d)
1.3.3 Data Space
Data Space accommodates all the data necessary
for processing the user program. This space com-
prises the RAM resource, the processor core and
peripheral registers, as well as read-only data
such as constants and look-up tables in Program
memory.
1.3.3.1 Data ROM
All read-only data is physically stored in program
memory, which also accommodates the Program
Space. The program memory consequently con-
tains the program code to be executed, as well as
the constants and look-up tables required by the
application.
The Data Space locations in which the different
constants and look-up tables are addressed by the
processor core may be thought of as a 64-byte
window through which it is possible to access the
read-only data stored in Program memory.
1.3.3.2 Data RAM/EEPROM
In ST62T42B and ST62E42B devices, the data
space includes 60 bytes of RAM, the accumulator
(A), the indirect registers (X), (Y), the short direct
registers (V), (W), the I/O port registers, the pe-
ripheral data and control registers, the interrupt
option register and the Data ROM Window Regis-
ter (DRW register).
Additional RAM and EEPROM pages can also be
addressed using banks of 64 bytes located be-
tween addresses 00h and 3Fh.
1.3.4 Stack Space
Stack space consists of six 12-bit registers which
are used to stack subroutine and interrupt return
addresses, as well as the current program counter
contents.
Table 4. Additional RAM/EEPROM Banks.
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10
ST62T42B/E42B
Device
2 x 64 bytes
RAM
2 x 64 bytes
EEPROM
Table 5. ST62T42B/E42B Data Memory Space
* WRIT E ONLY REGISTER
RAM/EEPROM BANK SELECT REGISTER
TIMER 1 STATUS/CONTROL REGISTER
TIMER 2 STATUS/CONTROL REGISTER
SPI INTERRUPT DISAB LE REGISTE R
LCD MODE CONTROL REGISTER
TIMER 1 PRESCALE R REGISTER
TIMER 2 PRESCALE R REGISTER
INTERRUPT OPTION REGISTER
PORT C DIRECT ION REGISTE R
DATA ROM WIND OW REGISTE R
PORT A DIRECTION REGISTE R
PORT B DIRECTION REGISTE R
ROM BANK SELECT REGISTE R
EEPROM CONTROL REGISTER
TIMER 1 COUNTE R REGISTER
TIMER 2 COUNTE R REGISTER
PORT C OPTION REGISTER
PORT A OPTION REGISTER
PORT B OPTION REGISTER
DATA ROM WINDOW AREA
A/D CONTROL REGISTER
PORT A DATA REGISTER
PORT B DATA REGISTER
PORT C DATA REGISTE R
WATCHDOG REGISTER
A/D DATA REGISTER
SPI DATA REGISTER
DATA and EEPROM
ACCUMULATOR
W REGISTER
X REGISTER
Y REGISTER
V REGISTER
RESERVED
RESERVED
RESERVED
RESERVED
RESERVED
RESERVED
DATA RAM
DATA RAM
LCD RAM
0C8h*
0C9h*
0CAh*
0CBh*
0CCh
0CDh
0CEh
0DAh
0DBh
0DCh
0DDh
0DEh
OFFh
03Fh
07Fh
0BFh
0C0h
0C1h
0C2h
0C3h
0C4h
0C5h
0C6h
0C7h
0CFh
0D0h
0D1h
0D2h
0D3h
0D4h
0D5h
0D6h
0D7h
0D8h
0D9h
0DFh
0E0h
0F7h
0F8h
0FEh
000h
040h
080h
081h
082h
083h
084h