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S1D13505 Interfacing to the NEC VR4121 Microprocessor
X23A-G-011-04 Issue Date: 01/02/05
4 VR4121 to S1D13505 Interface
4.1 Hardware Description

The NEC VR4121 microprocessor is specifically designed to support an external LCD

controller. It provides all the necessary in ternal address decoding and control sign als

required by the S1D13505.

The diagram below shows a typical implementation utilizing the S1D13505.

Figure 4-1: NEC VR4121 to S1D13505 Configuration Schematic

Note
For pin mapping see Table3-1:, Host Bus Interface Pin Mapping, on page 10.
WE1#
WE0#
DB[15:0]
WAIT#
RD#
BUSCLK
S1D13505
CS#
M/R#
RESET#
AB[20:0]
ADD21
SHB#
WR#
DAT[15:0]
LCDCS#
RD#
BUSCLK
LCDRDY
ADD[25:0]
NEC VR4121
Pull-up
BS#
RD/WR#
VDD(+3.3V)
System RESET
VDD
VDD3+3.3V
+2.5V
VDD2
Note:
When connecting the S1D13505 RESET# pin, the system designer should be aware of all
conditions that may reset the S1D13505 (e.g. CPU reset can be asserted during wake-up
from power-down modes, or during debug states).