EM65570
68COM/ 98SEG 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 the parallel interface is selected (P/S = “H”), D7-D0 are 8-bit bi-directional data
buses connecting to the MPU data bus.
When the 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 the 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 the 3-wire 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 the data conversion is completed or when making no access, be sure
to set SCL to “L”.
8-bit bi-directional bus. Connected to the MPU data bus.
D8-D15
CSB
I/O
I
Used as a data bus for the upper 8 pins in 16-bit access mode.
Chip Select input pin.
CSB = “L”: accepts access from MPU
CSB = “H”: denies access from 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”)
RDB
(E)
RDB is a data read signal. When RDB is “L”, D7-D0 are in output state.
Select 68-family MPU type (M86 = “H”)
R/WB = “H”: when E is “H”, D7-D0 are in output state.
R/WB = “L”: data on D7-D0 is latched at the falling edge of the E signal.
Read/Write control pin
Select 80-family MPU type (M86 = “L”)
WRB is a data write signal. Data on D7-D0 is 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
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Product Specification (V1.0) 09.05.2005
(This specification is subject to change without further notice)
ELAN [ ELAN MICROELECTRONICS CORP ]
