M37221 Mitsubishi, M37221 Datasheet - Page 7

• Manufacturer Part Number: M37221
• Description: SINGLE-CHIP 8-BIT CMOS MICROCOMPUTER for VOLTAGE SYNTHESIZER with ON-SCREEN DISPLAY CONTROLLER
• Manufacturer: Mitsubishi

MEMORY
Special Function Register (SFR) Area
The special function register (SFR) area in the zero page contains
control registers such as I/O ports and timers.
RAM
RAM is used for data storage and for stack area of subroutine calls
and interrupts.
ROM
ROM is used for storing user programs as well as the interrupt vector
area.
RAM for Display
RAM for display is used for specifying the character codes and col-
ors to display.
ROM for Display
ROM for display is used for storing character data.
Fig. 2. Memory map
for display (Note)
(62 K bytes)
(768 bytes)
(96 bytes)
(448 bytes)
ROM
RAM
RAM
RAM
0000
02C0
FFFF
00C0
00FF
021B
02FF
0300
05FF
0600
06B7
0800
FF00
FFDE
01FF
0217
16
16
16
16
16
16
16
16
16
16
16
16
16
16
16
16
Interrupt vector area
ROM correction
memory (RAM)
2 page register
SFR area
Not used
Not used
Not used
SINGLE-CHIP 8-BIT CMOS MICROCOMPUTER for VOLTAGE SYNTHESIZER
Zero page
Special page
M37221EF-XXXSP,M37221EFSP
Interrupt Vector Area
The interrupt vector area contains reset and interrupt vectors.
Zero Page
The 256 bytes from addresses 0000
page area. The internal RAM and the special function registers (SFR)
are allocated to this area.
The zero page addressing mode can be used to specify memory and
register addresses in the zero page area. Access to this area with
only 2 bytes is possible in the zero page addressing mode.
Special Page
The 256 bytes from addresses FF00
cial page area. The special page addressing mode can be used to
specify memory addresses in the special page area. Access to this
area with only 2 bytes is possible in the special page addressing
mode.
(8 K bytes)
for display
Note: Refer to Table 12. Contents of CRT display RAM.
ROM
with ON-SCREEN DISPLAY CONTROLLER
10000
11FFF
1FFFF
16
16
16
16
16
Not used
to FFFF
to 00FF
16
16
are called the zero
are called the spe-
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