PD64A_15 Datasheet, PDF (12/66 Pages) Renesas Technology Corp – 4-BIT SINGLE-CHIP MICROCONTROLLERS FOR INFRARED REMOTE CONTROL TRANSMISSION

2.4 Program Memory (ROM): 1002 steps × 10 bits (µPD64A)
2026 steps × 10 bits (µPD65)
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 7EAH to 7FFH cannot be used in the test program area.
(a) µPD64A
Figure 2-3. Program Memory Map
(b) µPD65
000H
10 bits
000H
10 bits
µPD64A, 65
Page 0
Page 0
3E9H
3EAH
3FFH
400H
Unmounted area^Note
7E9H
7EAH
7FFH
Test program area^Note
7E9H
7EAH
7FFH
Test program area^Note
Page 1
Note The unmounted area and test program area are designed so that a program or data placed in either of
them by mistake is returned to the 000H address.
2.5 Data Memory (RAM): 32 × 4 Bits
The data memory, which is a static RAM consisting of 32 × 4 bits, is used to hold processed data. The data
memory is sometimes processed in 8-bit units. R0 can be used as the ROM data pointer.
RF is also used as the ASR.
After reset, R0 is cleared to “00H” and R1 to RF hold the previous data (undefined when turning on the power).
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Data Sheet U14380EJ3V0DS00