Table of Contents
Advertisement
5. Data Memory (RAM)
The data memory consisting of 4 bits × 512 words is used to store data. These 512 words are expressed in a row address
(4 bits) and column address (4 bits). 348 words (row address = 04H to 1FH) within the data memory are addressed
indirectly by the G-register. Therefore it is necessary to specify the row address with the G-register before the data in this
area can be processed.
The addresses 00H to 0FH within the data memory are known as general registers, and can be used simply by specifying
the relevant column address (4 bit). These sixteen general registers can be used for operations and transfers with the data
memory, and may also be used as normal data memories.
Note: The column address (4 bits) that specifies the general register is the register number of the general
register.
Note: All row addresses (00H to 1FH) can be specified indirectly with the G-register.
Note: The LD and ST instructions can directly address 256 words of data memory (row address area 00H to
0FH).
*
Row addresses (04H to
2FH) indirectly specified
by G-register
Row address area
00H to 1FH can be
*
indirectly specified.
COLUMN ADDRESS: DC
0 1 2 3 4 5 6 7 8 9 A B C D E F
0
1
2
3
4
5
6
7
8
9
A
B
C
D
E
F
10
11
12
1D
1E
1F
15
TC9349AFG
General register
(any register within 000H to 00FH)
The LD and ST instructions can
directly specify row addresses
(00H to 0FH).
2006-02-24
Advertisement
Table of Contents
