PD17012_15 Datasheet, PDF (46/320 Pages) Renesas Technology Corp – 4-BIT SINGLE-CHIP MICROCONTROLLERS WITH DIGITAL TUNING SYSTEM HARDWARE

µPD17012, 17P012
5.5 Bank Register (BANK)
5.5.1 Configuration of bank register
Figure 5-5 shows the configuration of the bank register.
As shown in the figure, the bank register consists of 4 bits at address 79H (BANK) of the system register.
Actually, however, this register is a 2-bit register because the higher 2 bits are always fixed to 0.
Figure 5-5. Configuration of Bank Register
Address
Name
Symbol
Bit
Data
79H
Bank register
(BANK)
BANK
b3 b2 b1 b0
0 0ML
SS
BB
Power-on
0
Clock stop
0
CE
0
5.5.2 Function of bank register
The bank register specifies a bank of the data memory.
Table 5-1 shows the relationship between the value of the bank register and the bank of the data memory
specified by each value of the bank register.
Because the bank register exists on the system register, its contents can be rewritten no matter which bank
may be currently specified.
In other words, the bank register can be manipulated independently of the current status of the bank.
Table 5-1. Specifying Bank of Data Memory
Bank Register Data Memory
(BANK)
Bank
b3 b2 b1 b0
0 0 0 0 BANK0
0 0 0 1 BANK1
0 0 1 0 BANK2
0 0 1 1 Setting prohibited
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Data Sheet U10101EJ4V0DS