EM65571
130COM/128SEG 65K Color STN LCD Driver
6.3 System Bus Pins
Symbol
I/O
Description
Reset input pin.
RESB
I
When RESB is “L”, initialization is executed.
Data bus / Signal interface related pins.
When parallel interface is selected (P/S = “H”), the D7-D0 are 8-bit
bi-directional data busses, connected to the MPU data bus.
*When serial interface is selected (P/S = “L”), D0 and D1 (SCL, SDA)
are used as serial interface pins.
D0/SCL
D1/SDA
D2
SCL: Input pin for data transfer clock
SDA: Serial data input pin
I/O
D3/SMODE
D4.SPOL
D5-D7
SMODE: Serial transfer mode select pin
SPOL: RS pole select pin when 3-wires serial interface is selected.
SDA data is latched at the rising edge of SCL.
Internal serial/parallel conversion into 8-bit data occurs at the rising
edge of the 8th clock of SCL. After completing data transfer, or when
making no access, be sure to set SCL to “L”.
8-bit bi-directional bus. Connected to MPU data bus.
D8-D15
CSB
I/O
I
Used as a data bus for the upper 8 pins in the 16-bit access mode.
Chip Select input pin.
CSB = “L”: accepts access from the MPU
CSB = “H”: denies access from the MPU
RAM/Register select input pin.
RS
I
I
RS = “0”: D7-D0 are display RAM data
RS = “1”: D7-D0 are control register data
Read/Write control pin.
Select 80-family MPU type (M86 = “L”)
The RDB is a data read signal. When RDB is “L”, D7-D0 are in an
output status.
RDB
(E)
Select 68-family MPU type (M86 = “H”)
R/WB = “H”: When E is “H”, D7-D0 are in an output status.
R/WB = “L”: The data on D7-D0 are latched at the falling edge of the E
signal.
Read/Write control pin.
Select 80-family MPU type (M86 = “L”)
The WRB is a data write signal. The data on D7-D0 are latched at the
rising edge of the WRB signal.
WRB
(R/WB)
I
I
Select 68-family MPU type (M86 = “H”)
Read/Write control input pin.
R/W = “H”: Read
R/W = “L”: Write
MPU interface type selecting input pin.
M86 = “H”: 68-family interface
M86 = “L”: 80-family interface
Fixed at either “H” or “L”
M86
Product Specification (V1.0) 08.04.2005
• 15
(This specification is subject to change without further notice)
ELAN [ ELAN MICROELECTRONICS CORP ]
