W78C438C Datasheet, PDF (7/16 Pages) Winbond – 8-BIT MICROCONTROLLER

W78C438C
(A) EPMA.7 = 0
W78C438
P0
AP5
AP6
P1
AP7
DP4
P2
PSEN
P8
INT0
INT1
INT2
INT3
RD ^P3
WR
ADDR (20-bit)
\8
\8
\4
\8
EPROM
64K PROGRAM
DATA AREA
OE
RAM
ADDR 1MB
(20-bit)
DATA
WE
OE
When bit 7 of the EPMA is "1," AP7<3:0> are the output pins that support memory-mapped peripheral
chip select logic, which eliminates the need for glue logic. These pins are decoded by AP6<7:6>.
Only one pin is active low at any time. That is, they are active individually with 16K address
resolution. For example, CS0 is active low in the address range from 0000H to 3FFFH, CS1 is active
low in the address range from 4000H to 7FFFH, and so forth.
(B) EPMA.7 = 1
W78C438
P0
AP5
AP6
P1
DP4
P2
PSEN
P8
INT0
INT1
INT2
INT3
P3
AP7.0
AP7.1
RD
AP7.2
AP7.3
WR
ADDR (16-bit)
\8
\8
\8
EPROM
64K PROGRAM
DATA AREA
OE
\8
RAM
Device
ADDR (14-bit)
Device
\6
Device
0000h 4000h
8000h _C000h
DATA
3FFFh _7FFFh
BFFFh _FFFFh
(16k)
(16k)
(16k)
(16k)
WE
OE
Publication Release Date: July 1998
-7-
Revision A1