Samsung KS57C2308 Manual page 13

KS57C2308/P2308/C2316/P2316
DATA MEMORY (RAM)
OVERVIEW
In its standard configuration, the 512 x 4-bit data memory has four areas:
— 32 4-bit working register area in bank 0
— 224 4-bit general-purpose area in bank 0 which is also used as the stack area
— 224 4-bit general-purpose area in bank 1
— 32 4-bit area for LCD data in bank 1
— 128 4-bit area in bank 15 for memory-mapped I/O addresses
To make it easier to reference, the data memory area has three memory banks — bank 0, bank 1 and bank 15.
The select memory bank instruction (SMB) is used to select the bank you want to select as working data memory.
Data stored in RAM locations are 1-, 4-, and 8-bit addressable. One exception is the LCD data register area,
which is 1-bit and 4-bit addressable only.
Initialization values for the data memory area are not defined by hardware and must therefore be initialized by
program software following power
most of data memory contents are held.
. However, when
RESET
000H
WORKING REGISTERS
(32 x 4 Bits)
01FH
020H
GENERAL-PURPOSE
REGISTERS AND
STACK AREA
(224 x 4 Bits)
0FFH
100H
GENERAL-PURPOSE
REGISTERS
(224 x 4 Bits)
1DFH
1E0H
LCD DATA REGISTERS
(32 x 4 Bits)
1FFH
~
F80H
MEMORY-MAPPED I/O
AEERESS REGISTERS
(128 x 4 Bits)
FFFH
Figure 2-3. Data Memory (RAM) Map
signal is generated in power-down mode, the
RESET
BANK 0
BANK 1
~
BANK 15
ADDRESS SPACES
2-5