DS80C390_00 Datasheet, PDF (32/155 Pages) Dallas Semiconductor – High-Speed Microcontroller User’s Guide Supplement

DS80C390 High-Speed Microcontroller User’s Guide Supplement
Port 2 (P2)
7
6
5
4
3
2
1
0
SFR A0h A15/P2.7 A14/P2.6 A13/P2.5 A12/P2.4 A11/P2.3 A10/P2.2 A9/P2.1 A8/P2.0
RW-1 RW-1 RW-1 RW-1 RW-1 RW-1 RW-1 RW-1
R=Unrestricted Read, W=Unrestricted Write, -n=Value after Reset
P2.7-0
Bits 7-0
Port 2. The Port 2 pins function as an address bus during external memory
accesses, and a general purpose I/O port when executing code memory from the
internal 4KB SRAM (IDM1,IDM0 = 00b). When executing programs from the
internal 4KB SRAM, the contents of this SFR will be driven onto the Port 2 pins.
When executing programs from external memory, writes to P2 will have no effect
on the state of the Port 2 pins (except during register-indirect MOVX operations).
When executing register-indirect instructions such as MOVX A, @R1, this
register supplies the address MSB during data memory operations.
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