upd63a Renesas Electronics Corporation., upd63a Datasheet - Page 10

• Manufacturer Part Number: upd63a
• Description: 4-bit Single-chip Microcontroller For Infrared Remote Control Transmission
• Manufacturer: Renesas Electronics Corporation.

2.4 Program Memory (ROM): 512 steps
2.5 Data Memory (RAM): 32
memory is sometimes processed in 8-bit units. R0 can be used as the ROM data pointer.
10
The ROM consists of 10 bits per step, and is addressed by the program counter.
The program memory stores programs and table data, etc.
The 22 steps from 3EAH to 3FFH cannot be used in the test program area.
Note The unmounted area and the test program area are so designed that a program or data placed in either
The data memory, which is a static RAM consisting of 32
RF is also used as the ASR.
When reset, R0 is cleared to “00H” and R1 to RF retain the previous data (undefined when turning on the power).
3EAH
0FFH
1FFH
3E9H
3FFH
000H
100H
200H
of them by mistake is returned to the 000H address.
Test program area
Unmounted area
(a)
10 bits
PD63
Note
Note
768 steps
1002 steps
4 Bits
3E9H
3EAH
0FFH
1FFH
2FFH
3FFH
000H
100H
200H
300H
Figure 2-3. Program Memory Map
Test program area
Unmounted area
10 bits ( PD63)
10 bits ( PD63A)
10 bits ( PD64)
(b)
10 bits
PD63A
4 bits, is used to retain processed data. The data
Note
Note
3EAH
0FFH
1FFH
2FFH
3E9H
3FFH
000H
100H
200H
300H
Test program area
(c)
10 bits
PD64
PD63, 63A, 64
Note