es the Vacuum Fluorescent Display glass, VF drivers
CN1 - PARALLEL INTERFACE
Noritake Sales Office Tel Nos
C
N2 – SERIAL
INTERFACE
ELECTRICAL SPECIFICATION
SOFTWARE COMMAND SUMMARY
OPTICAL and ENVIRONMENTAL SPECIFICATIONS
CN1 Pin 3 Function
Async. Serial Mode
Font
CHARACTER SET
Font
*/RESET = JumperJ6.1&J6.2
BUSY = JumperJ6.2&J6.3
80.0 8.3
max 2.0 max
1.6 9.78
54.89 75.0 80.0
8.535
13.93 31.0 36.0
2.5 Pin 1
Pin 1
9.78
Dot Graphic VFD Module GU128x32D-7806A
q
q Single 5V Supply
q High Brightness Blue Green Display
q Operating Temp -40°C to +85°C
q 6 Multi Sized Fonts (Katakana / International)
q 4/8 Bit Parallel LCD & Serial Interfaces
CN1
and micro-controller ICs with refresh RAM, character generator and
interface logic. The 4/8 bit parallel & serial bi-directional interfaces are
5V TTL/CMOS compatible. The command set is LCD compatible with
extended graphic functions.
Pin 3 can be changed to /RESET or
BUSY terminal and selectable by
jumper J3 (2-3) or J3 (1-2)
J3 Function
2 & 3 / Reset
1 & 2 Busy
All J5 links & J6 should be open for
Parallel operation
CONTACT
Nagoya Japan: +81 (0)52-561-9867
Canada: +1-416-291-2946
Chicago USA: +1-847-439-9020
Munchen (D): +49 (0)89-3214-290
Itron UK: +44 (0)1493 601144
Rest Europe: +49 (0)61-0520-9220
www.noritake-itron.com
Subject to change without notice.
IUK Doc Ref: 11120 Iss:2 30 May 08
Parameter Symbol Value Condition
Power Supply Voltage VCC 5.0VDC +/- 5% GND=0V
Power Supply Current ICC 250mADC typ. VCC=5V
Logic High Input VIH 0.8VDC min. Vcc max. VCC=5V
Logic Low Input VIL 0VDC min 0.6VDC max. VCC=5V
Logic High Output VOH 3.5VDC min. Vcc max. IOH=-10uA
Logic Low Output VOL 0VDC min 0.6VDC max. IOL =4mA
ParameterValue
Display Area (XxY mm) 54.89 x 13.93
Dot Size/Pitch (XxY mm) 0.33 x 0.34 / 0.43 x 0.44
Luminance 800 cd/m2 Typ.
Colour of Illumination Blue-Green (Filter for colours)
Operating Temperature
Storage Temperature
Operating Humidity (non condensing)
-40°C to +85°C
-40°C to +85°C
20 to 80% RH @ 25°C
Instruction R/W RS D0-D7
Clear Display L L 01H
Cursor Return Home L L 02H
Entry Mode Set L L 04H-07H
Display ON/OFF L L 08H-0FH
Cursor Shift Left L L 10H
Cursor Shift Right L L 14H
Display Shift Left L L 18H
Display Shift Right L L 1CH
Select 4/8 bit interface L L
20H (4Bit) / 30H (8Bit) + luminance
Display Luminance L H 00H-03H (must follow above command)
Set CG RAM Addr. L L 40H-7FH
Set DD RAM Addr. L L 80H-E7H
Read BUSY/Addr. H L 00H-FFH D7 Busy = High
Read Data from RAM H H 00H-FFH
Set Graphic Cursor L L
Set Area Commands
L L
L H
L H
L H
L H
L H
Write Graphic Image L H
Set Font / Spacing / Line L L
F0H + xpos + ypos
F1H + x1 + y1 + x2 + y2 + cmd
where cmd 49H = Invert Area
46H = Fill Area
43H = Clear Area
4FH = Set Outline Box
6FH = Clear Outline Box
F1H + x1 + y1 + x2 + y2 + cmd + data
F2H + font style / line set
User Expansion Ports L L F4H-F8H Set, write and read user ports
Set RS Low 0FH Serial Comms. only
Read Data FEH Serial Comms. only
Read Cursor Position FFH Serial Comms. only
2.5
Standard Fonts LCD Katakana
UDF1
UDF2
UDF3
UDF4
UDF5
UDF6
UDF7
UDF8
UDF1
UDF2
UDF3
UDF4
UDF5
UDF6
UDF7
UDF8
NOTE: UDF characters are available using 5x7 font only.
Proportional Mini Font
J5
1-2 3-4 7-8
O O O 9600, N, 8, 1
L O O 19200, N, 8, 1
O L O 38400, N, 8, 1
X X L Self Test Mode
00H – FFH Write data to the display. In normal (LCD compatible) mode of operation, data is written to the display data
(DD RAM) or character generator (CG RAM).
When using the graphical data commands (F0H, F1H & F2H), data is written direct to the display and is not
stored in DD RAM. Data write busy times will increase when using the graphic functions.
Data Read
(40us – LCD compatible mode)
00H – FFH Read data from the display. In normal (LCD compatible) mode of operation, data is read from the display
data (DD RAM) or character generator (CG RAM)
Instruction / Busy time Data Format (RS = 0) Description
Status / Cursor Position
Read
(40us – LCD compatible mode)
Display Clear
(150µs)
Cursor Home
(500µs)
Entry Mode
(40µs)
00H - FFH D0 – D6 of read corresponds to the current cursor position. D7 shows the status of busy.
01H Fills all locations in the display data (DD) RAM with 20H (blank character). The address counter is set to 0 in
the DD RAM. The address counter is set to increment on each data read/write. Any display offset (using the
display shift command) is removed.
02H The address counter is set to 0 in the DD RAM. Any display offset (using the display shift command) is
removed.
04H – 07H Bit 1 is used to select the direction of the address counter on each data read o
counter is incremented. If set to ‘0’, the address counter is decremented.
Bit 0 enables the display to shift on each data read/write. If this bit is set to ‘1’, the display is shifted with the
cursor. The display shift direction depends upon the address counter direction (bit1). If this is set to
increment, the display is shifted left, if the address counter is set to decrement, the display is shifted right.
Note: When display shift is enabled, the data write busy time can increase by 150us.
Display Control
(50us)
08H-0FH Bit 2 is used to enable or disable the display. If this bit is set to ‘0’ the VFD’s power supply is turned off to
reduce power consumption.
Bit 0 enables the flashing block cursor. Note: If the cursor is enabled, busy times can increase by 20us.
Cursor Shift Left
(40us)
Cursor Shift Right
(40us)
Display Shift Left
(150us)
Display Shift Right
(150us)
Select 4 bit interface
(40µs)
10H Shift the cursor position (address counter) one position to the left.
14H Shift the cursor position (address counter) one position to the right.
18H Shift the display left, one character position.
1CH Shift the display right, one character position.
20H + lum (RS=1)
Enables 4-bit communications. Data is received on DB4-DB7 only. Two writes are required to send one data
byte. The most significant nibble should be sent first. Refer to the ‘Parallel Communications’ section for more
information. The lum value sets the displays brightness, and must be sent with the RS line high: 00H = full brightness, 01H = 75%, 02H = 50% & 03H = 25%.
Select 8 bit interface
(40µs)
Set CG Address
(40us)
Set DD Address
(40us)
Set Graphic Cursor
(40us)
*Note
Set Area
(40us + 500us[cmd byte])
30H + lum (RS=1)Enables 8-bit communications. Data is received on DB0-DB7. The lum value sets the displays brightness,
and must be sent with the RS line high: - 00H = full brightness, 01H = 75%, 02H = 50% & 03H = 25%.
40H – 7FH Set the character generator address (CG RAM). All written data is placed within the user definable character
area.
80H – E3H Set the display data address (DD RAM). 80H – 8FH = 1st line. C0H – CFH = 2nd line. 94H – A3H = 3rd line.
D4H – E3H = 4th line
Co-ordinates should be written with RS line set high.
F1H + x1 + y1 + x2 + y2 + cmd
Area Commands: - ‘I’ - invert area, ‘F’ – fill area, ‘C’ = clear area, ‘O’ – set outline, ‘o’ – clear outline.
All area commands should be preceded with the area co-ordinates. X1 Y1 left top X2 Y2 bottom right.
Co-ordinates, command and graphical data should be written with RS line set high.
Write Graphic Image
Set Font / Lines
(40us)
*Note
Port Configure
F1H + x1 + y1 + x2 + y2 + cmd
F2H + font / line number
F4H + byte
Image Commands: - ‘H’ – write horizontal graphical data with horizontal cursor movement.
‘V’ – write vertical graphical data with horizontal cursor movement.
‘h’ – write horizontal graphical data with vertical cursor movement.
‘v’ – write vertical graphical data with vertical cursor movement.
Graphical data should immediately follow the ‘H’, ’h’, ’V’ and ‘v’ commands.
Co-ordinates, command and graphical data should be written with RS line set high.
Select font type, font size and font spacing. Select number of lines to display in LCD emulation mode.
Font commands: ‘A’ or ‘a’ = 64 character mini-font.
‘B’ = 5x7 font with Katakana. ‘b’ = 5x7 font with International.
‘C’ = 10x14 font with Katakana. ‘c’ = 10x14 font with International.
‘D’ = 7x7 LCD font with Katakana. ‘d’ = 7x7 LCD font with International.
‘E’ = 7x15 font with Katakana. ‘e’ = 7x15 font with International.
‘F’ and ‘f’ = 20x28 font using pixel doubling of ‘C’ and ‘c’.
Font spacing: ‘P’ = Proportional, ‘M’ = Mono-spaced, ‘1’ or ‘2’ = 1 / 2 pixel inter-character spacing
Display Lines: ‘L’ = 2 Lines with 7x7 fonts, ‘3’ = 3 Lines with 7x7 fonts, ‘4’ = 4 Lines with 7x7 fonts.
Font / line commands should be written with RS line set high.
Bit 7 High = I/O Port, Low = Serial Port. See extended port and serial commands.
Read Port Status F5H The current port status is read with RS high. See extended port and serial commands.
Port Out / Serial Send
F6H + byte byte is output from the port. In serial mode check the busy status before sending again.
Port In / Serial Read F7H The current port levels or buffered received data can be read with RS high.
Port Buffer Send
F8H + size + data
Up to 128 bytes of data can be buffered before being transmitted from the serial port.
Instruction / Busy time Data Format Additional Serial Data Commands
Set RS Low 0FH Set the RS line low for the following byte only. Used in serial communications only.
Read Data FEH Read data at current cursor position. This command is used with serial communications only.
Read Cursor Position FFH Read current cursor position. This command is used with serial communications only.
Note: After these commands are executed, the cursor will be disabled and any character data will be written to the display only, and not the DD RAM. Any subsequent LCD compatible command will
re-enable the cursor and allow for DD RAM writing.
NORITAKE ITRON VFD MODULES GU128x32D-7806A
Page 3
8-Bit Data Read Timing Diagram.
8-Bit Data Write Timing D
iagram.
.
UPPER NIBBLE
LOWER NIBBLE
command to set either 4 or 8 bit mode.
Dot Graphic VFD Module GU128x32D-7806A
GRAPHICAL DATA WRITES
X1, Y1
DATA
DIRECTION
Vertical Data & Horizontal
Movement
MSB
X1, Y1
MSB
DATA
DIRECTION
Vertical Data & Vertical
Movement
X1, Y1
MSB
Horizontal Data & Horizontal
DATA
DIRECTION
Movement
X1, Y1
DIRECTION
MSB
Horizontal Data & Vertical
Movement
DATA
PARALLEL COMMUNICATIONS
This module has a fast latching 8-bit data bus. The ‘RS’ and ‘R/W’
control lines should be set prior to the rising edge of the ‘E’ enable line.
Data is clocked in on the falling edge of the enable line. The busy line
should be checked before sending data.
HOST
SYSTEM
I/O
I/O
I/O
I/O
I/O
D0-7
GU128x32D-7806A
E
RS
R/W
BUSY
VDD GND VDD GND
The busy state can be monitored on D7 when reading the DDRAM
address (RS line low). The busy state can also be monitored directly
from CON1 pin 3 if link J3 is set to 1&2.
R/W
RS
E
D0-D7
BUSY
R/W
>30ns
>30ns
>25ns
>20ns
>100ns
<120ns
tBUSY
HOST
SYSTEM
I/O
I/O
I/O
I/O
I/O
D4-7
GU128x32D-7806A
E
RS
R/W
BUSY
4-Bit Data/Command Write Timing Diagram
R/W
RS
>30ns
E
D4-D7
BUSY
>25ns
>20ns
>100ns
RS
>250ns
E
<250ns >50ns
D0-D7
The data bus width can be selected for 4-bit operation, using data lines
D4-D7. Within this mode, two writes are required to send one data byte.
VALID
The high nibble (bits 4-7) should be sent first, followed by the low nibble
(bits 0-3). The busy state is not triggered between nibbles. It is
VDD GND VDD GND
>100ns
important that the status is NOT read within 40us of sending the
>25ns
>20ns
<120ns
>100ns
tBUSY
NORITAKE ITRON VFD MODULES GU128x32D-7806A
Page 4
D0 D1 D2 D3 D4 D5 D6 D7 START
STOP
TXD
LOWER NIBBLE
UPPER NIBBLE
Dot Graphic VFD Module GU128x32D-7806A
4-Bit Data/Status Read Timing Diagram.
R/W
RS
>30ns >250ns
E
>250ns
D4-D7
<250ns
>50ns
100ns
>250ns
Valid Valid
>50ns
ASYNCHRONOUS SERIAL COMMUNICATION
Asynchronous & synchronous serial interfaces are provided at TTL level. Synchronous is enabled with parallel, first received byte disables the
other. To enable Asynchronous Serial Mode connect pin 4 and 6 on CN2 (LINK1 and LINK2), Link J6 and enable i80 Mode on J2 and J4. When
using Asynchronous serial communications, the module is automatically initialized at power-up/reset with the cursor enabled.
HOST
SYSTEM
TXD
RXD
DTR
CTS
RXD
TXD
GU128x32D-7806A
HB
MB
VDD GND VDD GND
Host to Module Write
Module to Host Write
The host busy line (HB) stops the module from sending data
<200us
to the host. The use of the HB and MB lines are optional, and
can be connected together if not required.
SYNCHRONOUS SERIAL COMMUNICATION
With synchronous communications enabled, data can be clocked into the VFD module on the rising edge of SCK, with the MSB sent first. The host
must provide adequate delays for the module to process the data, these busy times are specified in the software command section. Alternatively
the host can monitor the MB (Module Busy) line.
HOST
SYSTEM
I/O
I/O
I/O
I/O
I/O
SIN
SOUT
SCK
/SS
MB
GU128x32D-7806A
VDD GND VDD GND
The /SS pin can be used as an enable pin if other devices are
connected to the serial line, and also allows byte synchronisation.
The use of the /SS line is recommended, but can be permanently
pulled low if not required.
>125ns
SCK
MOSI
MISO
MB
/SS
TTL Synchronous serial communication.
>250ns
>250ns
MSB LSB
MSB LSB
>250ns
<20us tBUSY
>250ns
SERIAL CONTROL
An additional command has been included to distinguish between command and data writes when using serial communications. This command
(0FH) will temporarily set the RS line low for the subsequent written byte. The following example displays two text messages using the serial
communications and the ‘Set RS’ command: -
This module features a command set that is LCD compatible, allowing easy replacement in existing equipment with little or no modifications.
Careful consideration should be taken regarding the command execution times of this module. Although the commands can be executed within
40us, which is normal for LCD, busy times are increased when using the scroll write modes and with the cursor enabled. When using the 4-bit
parallel mode, a 40us delay is required between nibbles. Also reading back data in 4-bit parallel mode is not supported. DD RAM address
locations 70H+ are used to access the extended graphic commands.
At power up and reset the module is automatically initialised and ready to receive data. The interface is set to 8-bit, the display is cleared, the
cursor position is set to the top-left corner (DD RAM address = 00H), and the display luminance is set to 100%. The display defaults to 2-line LCD
emulation mode with a 7x7 font.
RESET
At power ON the modules internal reset requires at least 8ms before commands can be sent. Please check the busy status. If you connect pin 3
to the hardware reset using jumper 3, the module will require 3ms to re-initialize. Reset is achieved by high-low-high transition of at least 100ns.
EXTENDED GRAPHIC COMMANDS Command Structure and Values Copyright 2007 Noritake Co Limited, Japan
In addition to the standard LCD commands, this module includes additional commands to display graphical data, different font sizes, fill, clear
and invert defined areas of the display. Also an outline command is available to draw rectangles around objects. When any of these extended
commands are executed, the module will change to the ‘graphics’ mode of operation. This graphics mode allows text to be written to any part of
the display.
There are many differences the user should be aware of when the display is in this graphics mode: -
The graphics mode is disabled as soon as any valid LCD command is received.
Written data may require additional busy times.
Text data is not written into the DD RAM and therefore can not be read back.
Graphical text can not be shifted onto the display.
The cursor is disabled & cursor direction is set to increment only.
UDF characters cannot be written.
DISPLAYING GRAPHICAL TEXT
The module contains 3 font sizes, a proportional 5x5 dot mini-font, 5x7 dot font, and a
10x14 dot font. Graphical text can be written to any part of the display using the ‘Set
Graphic Cursor’ command (F0H). Characters are positioned above the current cursor
position. Each character written will include either a one pixel or two pixel space to the right
side of the character. After each character is written to the display, the cursor position is
automatically advanced. If the cursor position reaches the end of the display, the host must
reposition to the next line.
The following example displays two text messages in the center of the display using the
standard 5x7 character font. Command bytes that are underlined should be sent with RS
line low.
0,0
0,7
6,7
from cursor position 0,7.
The next example displays one line of text using the 10x14 character font. Command bytes
that are underlined should be sent with RS line low.
Graphical images can be displayed on the VFD module in either a horizontal or vertical byte orientation. After each graphical data write, the cursor
is automatically advanced. All graphical data is contained within the defined area. Unused bits are masked where the screen area is not a byte
The following example displays a simple graphical image. The graphical data orientation is
set to horizontal data format, with a vertical cursor movement. Command bytes that are
underlined should be sent with RS line low.
The next example displays a simple graphical image using a vertical data format, with a
horizontal cursor movement. Command bytes that are underlined should be sent with RS
line low.
GRAPHIC DATA AREA COMMAND AREA CO-ORDINATES VERTCAL FORMAT
The following example displays three options for the user to select, each option is contained within a box with a shadow effect. Drawing horizontal
and vertical lines using the fill area command creates the shadow effect. Command bytes that are underlined should be sent with RS line low.
1-PIXEL SPACING
DISPLAY TEXT SET CURSOR 5x7 FONT
Displaying graphic images in vertical and horizontal format.
The next example uses the invert area command to select one of the options.
TOP LEFT SET AREA BOTTOM RIGHT
INVERT
Drop Shadows created with the ‘Fill Area’ command.
F1H 50H 0BH 71H 13H ‘I’
NORITAKE ITRON VFD MODULES GU128x32D-7806A
Option ‘Run’ selected with the ‘Invert Area’ command.
Page 7
POR
T I/O MODE
MOSI I/O
RXD I/O SCK I/O 1 HB I/O MB I/O TXD I/O MISO I/O
D7 D6 D5 D4 D3 D2 D1 D0
A ‘1’ defines the port as an input, ‘0’ an output. All ports are subsequently
MOSI OUT
RXD OUT
SCK OUT
-
HB OUT MB OUT TXD OUT
MISO OUT
D7 D6 D5 D4 D3 D2 D1 D0
EXTENDED
PORT AND
SERIAL COMMANDS
MOSI IN RXD IN SCK IN - HB IN MB IN TXD IN MISO IN
D7 D6 D5 D4 D3 D2 D1 D0
SYNCHRONOUS SERIAL MODE
transmission.
Data is transmitted to the synchronous serial port. If the ‘HNDSHK’ bit is
port is set high with a ‘1’ and low with a ‘0’. Busy detection is
enabled by setting HNDSHK to a ‘1’. The default clock level is high with
DEF H/L set to a ‘1’, low if ‘0’. The CLK EDGE is set to rising with a ‘1’,
is set with the SPEED1/0 bits,
The current port status is read with RS high. TX PEND shows data is
pending for transmission, TXC transmission completed, and RXC shows
data received. HB IN shows the current state of the ‘HB’ line. TXC is
ed data byte can be read with RS high. The host
should first check the RXC bit using the PORT STATUS command. After
CLK EDGE
SPEED1 SPEED0 0 0 TXD OUT
HNDSHK
DEF H/L
D7 D6 D5 D4 D3 D2 D1 D0
TXC RXC - - - - HB IN TX PEND
D7 D6 D5 D4 D3 D2 D1 D0
to the
synchronous serial port. If the ‘HNDSHK’ bit is enabled, transmission is
delayed until HB line is low.
A ‘1’ sets the corresponding port high, and a ‘0’ sets it low. If the port is
Dot Graphic VFD Module GU128x32D-7806A
The extended port and serial commands are only valid when the display is connected to the host using the parallel interface.
Command Structure and Values Copyright 2007 Noritake Co Limited, Japan
The I/O mode gives direct access to the 7 control lines on the serial
connector; HB, MB, TXD, RXD, MISO, MOSI and SCK. Each line can be
individual set to an Input or Output using the ‘PORT CONFIGURE’
command. All inputs include an optional pull-up resistor, 30K-120K in
value. The outputs can source ~5mA and sink ~30mA. There are 3
commands available to configure port, set port level and read port state.
Example: -
F4H 82H - Set RXD to input and other ports to
F6H 02H - Turn on LED1&2 by setting HB & MB
F7H - Read port, D1 is the switch state.
outputs.
low. Enable internal pull-up resistor on
RXD.
LED1 LED2
SW1
VCC
HB
MB
RXD
GND
7806A
PORT CONFIGURE F4H + I/O
set low.
PORT OUT F6H + OUT
set to an input, a ‘1’ will enable the internal pull-up resistor.
PORT IN F7H
The current port levels are read with RS high.
This mode gives the ability to control external synchronous devices
connected to the serial connector. Data is transmitted and received on
each ‘PORT OUT’ command. The received data byte is buffered until
the ‘PORT READ’ command is executed.
The ‘PORT BUFFER SEND’ command will buffer up to 128 bytes of
data prior to transmission; only the last data byte received is captured
when using this command.
The ‘PORT CONFIGURE’ command will set the MOSI & SCK lines to
outputs, and the MISO line to an input. The HB line is used as an
optional busy input, and the MB line is set to an output. The TXD line is
also set to an output, and this can be used as a reset or device select
control line.
The serial transmission is defined by the ‘DEF H/L’ (default clock level
high or low), ‘CLK EDGE’ (rising or falling clock edge), and the ‘SPEED’
(clock speed) control bits. The ‘HNDSHK’ bit is used to detect the status
of the HB line prior to data transmit. All data is transmitted MSB first.
A ‘STATUS READ’ command can be used to check for completed data
PORT CONFIGURE F4H + SETUP
The TXD
and falling with a ‘0’. The clock speed
00=4Mhz, 01=1Mhz, 10=250kHz, 11=125kHz.
SERIAL SEND F6H + DATA
enabled, transmission will be delayed until the HB line is pulled low.
PORT BUFFER SEND F8H + SIZE + DATA
A maximum of 128-bytes of data is buffered before transmission
READ PORT STATUS F5H
Example: -
F4H 1BH - Enable Synchronous mode with busy test; clock speed to
F6H 55H - Send byte 55H to synchronous port when HB line is low.
F5H - Read current status. Wait until TXC is set.
F5H - Read current status. Check if RXC is set.
F7H - Read received byte.
F8H 16H “This is a test string.” - Send character string when HB line is low.
F5H - Read current status. Wait until TXC is set.
125kHz, data clocked on falling edge, default clock level is low.
cleared after status read.
SERIAL READ F7H
The currently buffer
reading the data byte, the RXC bit is cleared.
NORITAKE ITRON VFD MODULES GU128x32D-7806A
Page 8
Data is transmitted to the asynchronous serial port. If the ‘HNDSHK’ bit is
The MISO port is set high with a ‘1’ and low with a ‘0’. Busy detection is
enabled by setting HNDSHK to a ‘1’. The parity is set with the PARITY1/0
11=odd. The baud rate is set with the
The current port status is read with RS high. TX PEND shows that data is
pending for transmission, TXC transmission was completed, and RXC
shows data has been received. RX ERR indicates a received parity,
hows the current state of the ‘HB’ line.
The currently buffered data byte can be read with RS high. The host
should first check the RXC bit using the PORT STATUS command. After
ASYNCHRONOUS SERIAL MODE
PARITY0
BAUD1 BAUD0 0 1
MISO OUT
HNDSHK
PARITY1
D7 D6 D5 D4 D3 D2 D1 D0
TXC RXC RX ERR - - - HB IN TX PEND
D7 D6 D5 D4 D3 D2 D1 D0
othe
asynchronous serial port. If the ‘HNDSHK’ bit is enabled, transmission is
Dot Graphic VFD Module GU128x32D-7806A
This mode gives the ability to control external asynchronous devices
connected to serial connector. Data is transmitted on each ‘PORT OUT’
command. Data received is held within a 1 byte buffer until the ‘PORT
READ’ command is executed.
The ‘PORT BUFFER SEND’ command will buffer up to 128 bytes of
data prior to transmission.
The ‘PORT CONFIGURE’ command will set the TXD & MB lines to
outputs, and the RXD line to an input. The MISO line is also set to an
output, and this can be used as a reset or device select control line. The
HB line is used as an optional busy input. The MB line mirrors the RXC
status flag, and indicates that data has been received.
A ‘STATUS READ’ command can be used to check for completed data
transmission.
Data Write Example: -
F4H 5AH - Enable Asynchronous mode with busy test; set interface to 19200E.
F6H 55H - Send byte 55H to asynchronous port when HB line is low.
F5H - Read current status. Wait until TXC is set.
F6H AAH - Send byte AAH to asynchronous port when HB line is low.
F8H 16H “This is a test string.” - Send character string when HB line is low.
F5H - Read current status. Wait until TXC is set.
Data Read Example: -
F5H - Read current status. Repeat until RXC is set.
F7H - Read received byte.