40
µPD750008 USER'S MANUAL
Figure 3-7. µPD750008 I/O Map (1/5)Notes 1. Can be manipulated separately as the RBS and MBS in 4-bit units.Can also be manipulated as the BS in 8-bit units.Use SEL MBn and SEL RBn instructions to write data to MBS and RBS respectively.2. WDTM: Watchdog timer enable flag (W); cannot be cleared by an instruction.
F80H
F82H
F83H
F85H
F86H
F8BH
F98H
Address
b3 b2 b1 b0
Hardware name (symbol)
R/W
1 bit 4 bits 8 bits
Remarks
Number of bits that can be 
manipulated
R/W
R
––
Note 1
Bit 
manipulation 
addressing
Stack pointer (SP)
Register bank selection register (RBS)
Bank selection register (BS)
Memory bank selection register (MBS)
Basic interval timer mode register (BTM)
Basic interval timer (BT)
WDTM
Bit 0 is fixed 
to 0.
Only bit 3 can 
be manipulated.
W
W
R
––
––
mem.bit
mem.bit
Clock mode register (WM) R/W
––
(R)
mem.bit
Only bit 3 can 
be tested.
F84H Stack bank selection register (SBS) R/W mem.bit
Note 2