W78958B Datasheet, PDF (7/28 Pages) Winbond – 8-BIT EMULATION MICROCONTROLLER

W78958B
AP5.7−AP5.0 Address Bus, Bits 7−0
TYPE
MODE
DESCRIPTION
Advanced
Normal
AP5<7:0> output the <7:0> address of the external ROM multiplexed
with the <7:0> address of the external data RAM.
Emulation
When ESEL is held at "L" level, AP5 is the low-byte address input for
the SFR/PC and internal RAM. When ESEL is held at "H" level, AP5
is in high impedance state.
Standard
Normal
Pins ROMS1 and ROMS0 determine functions of AP5. For details,
see Table D3.
Emulation Same as in the advanced type.
ROMS1
0
0
1
1
ROMS0
0
1
0
1
FUNCTIONS of AP5
AP5 output the <7:0> address of the external 4K EPROM.
AP5 output the <7:0> address of the external 8K EPROM.
AP5 output the <7:0> address of the external 16K EPROM.
AP5 output the <7:0> address of the external 32K EPROM.
Table D3.
AP6.7−AP6.0 Address Bus, Bit 15−8
TYPE
MODE
DESCRIPTION
Advanced
Normal
AP6<7:0> output the <15:8> address of the external ROM
multiplexed with the <15:8> address of the external data RAM.
During the execution of "MOVX @Ri," AP6's output comes from the
HB register, which is the page register for the high byte address.
Emulation
When ESEL is held at "L" level, AP6<0> is the address input for the
accesses to the SFR/PC and internal RAM. At this time, if AP6<0> =
0, the SFR/PC can be accessed; if AP6<0> = 1, the internal RAM
can be accessed. When ESEL is held at "H" level, AP6 is in high
impedance state.
Standard
Normal
Pins ROMS1 and ROMS0 determine functions of AP6. For details,
see Table D4.
Emulation Same as in the advanced type.
Publication Release Date: September 1997
-7-
Revision A3