UPD61P24CS NEC, UPD61P24CS Datasheet - Page 5

• Manufacturer Part Number: UPD61P24CS
• Description: 4-BIT SINGLE-CHIP MICROCONTROLLER FOR REMOTE CONTROL TRANSMISSION
• Manufacturer: NEC

3.
4.
data memory is processed in 8-bit units. R
Caution Avoid using the RAM areas R
The program memory (ROM) is configured in 10 bits steps. It is addressed by the program counter.
Program and table data are stored in the program memory.
The data memory is a RAM of 32 words
After power application, the RAM will be undefined. The RAM retains the previous data on reset.
PROGRAM MEMORY (ROM) ……… 1002 STEPS
DATA MEMORY (RAM) ……… 32 WORDS
areas are also used as stack memory areas (to prevent program hang-up in case the value of the
SP is destroyed due to some reason such as noise).
When using these RAM areas as general-purpose RAM areas, be sure to include stack pointer
checking in the main routine.
3EAH
0FFH
1FFH
2FFH
3E9H
3FFH
000H
100H
200H
300H
Figure 4-1. Data Memory Organization
1
Figure 3-1. Program Memory Map
D
, R
0
may be used as the data pointer for the ROM.
5 bits. The data memory stores processing data. In some cases, the
E
, and R
0
F
in a CALL routine as much as possible because these
R
R
R
R
. .
.
. .
.
5 BITS
C
B
F
0
10 BITS
Test program
area
SP–3
SP–2
SP–1
SP–0
PD61P24
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