SSD1858 Solomon Systech, SSD1858 Datasheet - Page 17

• Manufacturer Part Number: SSD1858
• Description: LCD Segment / Common Driver
• Manufacturer: Solomon Systech

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R/W(WR)
SSD1858
data bus
E(RD)
7
7.1
7.2
7.3
FUNCTIONAL BLOCK DESCRIPTIONS
Command Decoder and Command Interface
This module determines whether the input data is interpreted as data or command. Data is
directed to this module based upon the input of the D/C# pin. If D/C# is high, data is written to
Graphic Display Data RAM (GDDRAM). If D/C# is low, the input at D
command and it will be decoded and written to the corresponding command register.
Reset is of the same function as Power ON Reset (POR). Once RES# receives a negative reset
pulse of about 1us, all internal circuitry will be back to its initial status. Refer to Command
Description section for more information.
MPU Parallel 6800-series Interface
The parallel interface consists of 8 bi-directional data pins (D
and CS#. R/W(WR#) input High indicates a read operation from the Graphic Display Data RAM
(GDDRAM) or the status register. R/W(WR#) input Low indicates a write operation to Display
Data RAM or Internal Command Registers depending on the status of RS input. The E(RD#)
and CS# input serves as data latch signal (clock) when they are high and low respectively.
Refer to Figure 14 of parallel timing characteristics for Parallel Interface Timing Diagram of
6800-series microprocessors.
In order to match the operating frequency of display RAM with that of the microprocessor, some
pipeline processing is internally performed which requires the insertion of a dummy read before
the first actual display data read. This is shown in Figure 3 below.
MPU Parallel 8080-series Interface
The parallel interface consists of 8 bi-directional data pins (D
and CS#. The CS# input serves as data latch signal (clock) when it is low. Whether it is display
data or status register read is controlled by D/C#. R/W(WR#) and E(RD#) input indicates a write
or read cycle when CS# is low. Refer to Figure 16 of parallel timing characteristics for Parallel
Interface Timing Diagram of 8080-series microprocessor.
Similar to 6800-series interface, a dummy read is also required before the first actual display
data read.
writ e column address
Figure 3 – Display Data Read with the insertion of Dummy Read
Rev 1.1
09/2002
N
dummy read
data read1
n
data read 2
n+1
0
0
- D
- D
7
7
), R/W(WR#), D/C#, E(RD#)
), R/W(WR#), E(RD#), D/C#
0
-D
7
is interpreted as a
data read 3
n+2
SOLOMON
12