33
µ
PD17062
5.1.4 Structure of Port Data Registers (port register)
The port registers consist of 12 nibbles at addresses 70H to 73H of the banks of data memory.
Fig. 5-5 shows the structure of the port registers.
As shown in Fig. 5-5, the same port registers are allocated in BANK0 and BANK2. Thus, the port registers
actually consist of eight nibbles.
Fig. 5-5 Structure of Port Registers
5.1.5 Structure of General-Purpose Data Memory
General-purpose data memory consists of that part of memory other than the system register and the port
registers of data memory.
General-purpose data memory consists of a total of 336 words, with 112 words in each of BANK0 to BANK2.
5.1.6 Unmounted Data Memory
As shown in Fig. 5-6, nothing is assigned to bit 0 of address 72H in BANK1 of the port registers. For an
explanation of this address, see Section 5.3.2.
70H 71H 72H 73H
P0A P0B P0C P0D
P1A P1B P1C Fixed at 0
BANK0
BANK2
BANK1
Port register
Address
Symbol