PD17225_15 Datasheet, PDF (21/86 Pages) Renesas Technology Corp – 4-BIT SINGLE-CHIP MICROCONTROLLER FOR SMALL GENERAL-PURPOSE INFRARED REMOTE CONTROL TRANSMITTER

µPD17225, 17226, 17227, 17228
2.4.4 Data buffer (DBF)
The data buffer on the addresses 0CH to 0FH of data memory is used for data transfer to and from peripheral hardware
and for storage of data during table reference.
(1) Functions of the data buffer
The data buffer has two major functions: a function to transfer to and from hardware and a function to read
constant data from the program memory (for table reference). Figure 2-7 shows the relationship between the
data buffer and peripheral hardware.
Figure 2-7. Data Buffer and Peripheral Hardware
Data buffer
(DBF)
Internal bus
Program memory
(ROM)
Constant data
Peripheral
address
05H, 06H
03H, 04H
Peripheral hardware
8-bit timer
(TMC, TMM)
Carrier generator for
remote controller
(NRZLTMM, NRZHTMM)
40H
Address register (AR)
Data Sheet U12643EJ2V0DS00
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