PT6314_10 Datasheet, PDF (28/42 Pages) Princeton Technology Corp – Dot Character VFD Controller/Driver IC

PT6314
6.11 “READ DATA FROM CGRAM OR DDRAM” INSTRUCTION
RS R/W DB7 DB6 DB5 DB4 DB3 DB2 DB1 DB0
CODE 1
1
D
D
D
D
D
A
D
D
←High Order Bit
Low Order Bit→
The above instruction reads the 8 bits binary data “DDDDDDDD” from the CGRAM or DDRAM. The “CGRAM or
DDRAM Address Set” instruction must be executed first before this instruction can be entered. If the “CGRAM or
DDRAM Address Set” is not executed prior to the “READ Data from CGRAM or DDRAM” then the first READ data
becomes invalid. When “Read” Instructions are serially executed, the next address data is normally read from the
second “Read”. Before the cursor shifts by the “Cursor or Display Shift” Instruction, the address set instruction do not
need to be executed before the read instruction (only applies to DDRAM). The operation of the cursor shift instruction is
the same as the “DDRAM Address Set” Instruction.
After reading one data, the value of the address is automatically increased or decreased by 1 in accordance to the
selection made in the “Entry Mode”. Please note that the address counter is automatically increased or decreased by 1
after “Write Data to CGRAM or DDRAM” Instruction is executed. At this moment, the address counter’s target data
cannot be read if the “Read Data from CGRAM or DDRAM” Instruction is executed. Thus, to read data correctly, the
“Address Set” or “Cursor Shift” (if Read Data from DDRAM only) Instruction must be executed before reading.
6.12 POWER ON RESET
When PT6314 is initialized, the internal status after power supply has been reset is as follows:
1. Display Clear: 20H (space code) fills the DDRAM
2. Address Counter is set to 00H
3. Address Counter is pointed to the DDRAM
4. Display ON/OFF: D=0, C=0, B=0 (Display OFF)
5. Entry Mode Set: I/D=1, S=0 (Increment, Cursor Shifts are enabled)
6. Function Set: DL=1, N=1 (8-Bit MCU Interface, 2-Line Display are enabled.)
7. Brightness Control: BR0=BR1=0 (Brightness = 100%)
For the MCU Interface and Duty Ratio Selection, please refer to the table below.
Pin Name
TEST IFSEL DS1 DS0
Function
Remarks
0
X
X
X Self Test Mode
This is effective specially after long usage.
1
0
X
X Serial Interface
SI/SO, SCK, STB
1
1
X
X Parallel Interface
RS, E, R/W, DB7 to DB4 or DB7 to DB0
1
1
1
X
X
X
0
0
1
0
1
0
Duty=1/16(16Cx1 or 2L Display)
Duty=1/20(20Cx1 or 2L Display)
Duty=1/24(24Cx1 or 2L Display)
It does not need to use the extension driver.
The number of display lines is selected by instruction.
1
X
1
1
Duty=1/40(40Cx1 or 2L Display)
Extension driver must be used. The number of display
lines is selected by instruction.
The above table shows the relationship between the status of PT6314 and the pin states during RESET.
V1.5
28
October 2009