UPD6P8 NEC [NEC], UPD6P8 Datasheet - Page 16

• Manufacturer Part Number: UPD6P8
• Description: MOS INTEGRATED CIRCUIT 4-BIT SINGLE-CHIP MICROCONTROLLER FOR INFRARED REMOTE CONTROL TRANSMISSION
• Manufacturer: NEC [NEC]

3.5 Data Memory (RAM): 32
memory is sometimes processed in 8-bit units. R0 can be used as the ROM data pointer.
16
The data memory, which is a static RAM consisting of 32
RF is also used as the ASR.
After reset, R0 is cleared to 00H and R1 to RF retain the previous data (undefined when turning on the power).
Notes 1. R0 alternately functions as the ROM data pointer (refer to 3.6 Data Pointer (DP)).
2. RF alternately functions as the PC address stack (refer to 3.3 Address Stack Register (ASR (RF)).
Figure 3-4. Data Memory Configuration
4 Bits
R
1n
(higher 4 bits) R
Data Sheet U17848EJ3V0DS
R
R
R
R
R
R
R
R
R
R
R
R
R
R
R
R
1A
1B
1C
1D
1E
1F
10
11
12
13
14
15
16
17
18
19
RA
RB
RC
RD
RE
RF
R0
R1
R2
R3
R4
R5
R6
R7
R8
R9
0n
(lower 4 bits)
R
R
R
R
R
R
R
R
R
R
R
R
R
R
R
R
0C
0D
00
01
02
03
04
05
06
07
08
09
0A
0B
0E
0F
4 bits, is used to retain processed data. The data
Note 1
Note 2
PD6P8, 6P8A, 6P8B