Page 12 Epson Research and Development
Vancouver Design Center
S1D13504 Interfacing to the Motorola MC68328 "Dragonball" Microprocessor
X19A-G-013-02 Issue Date: 01/02/02
If UDS and/or LDS are required for their alternate I/O functions, then the 68328 to
S1D13504 interface may be realized using the S1D13504 Generic bus interface mode. Th e
electrical connections required for this interface are shown b elow. Not e that in e ither case ,
the DTACK signal must be made available for the S1D13504, since it inserts a variable
number of wait states depending upon CPU/LCD synchronization and the LCD panel
display mode being used. A single resistor is used to speed up the rise time of the WAIT#
(TA) signal when terminating the bus cycle.
Figure 4-2: Block Diagram of MC68328 to S1D13504 Interface - Generic Interface Mode
The S1D13504 requires a 2M byte address space for the display buffer, plus a few more
locations to access its internal registers. To accommodate t his rel atively large b lock siz e, it
is preferable to use one of the chip selects from groups A or B, but this is not required.
Virtually any chip select other than CSA0 or CSD3 would be suitable for the S1D13504
interface.
MC68328 S1D13504
A[20:1]
D[15:0]
DTACK
UWE
LWE
OE
CLK0
AB[20:1]
SD[15:0]
CS#
WAIT#
WE1#
WE0#
RD1#
RD0#
BUSCLK
RESET#
Vcc
470
A21 M/R#
CSB3
Note:
When connecting the S1D13504/55 RESET# pin, the system designer should be aware of all
conditions that may reset the S1D13504/55 (e.g. CPU reset can be asserted during wake-up
from power-down modes, or during debug states).
System RESET