40
eDisplay (OP7200)
3.7 Liquid Crystal Display Controller
The LCD module controller chip provides support for the LCD module. The controller
chip is attached to the data bus on the OP7200’s RabbitCore module, and is mapped to the
I/O address space. This interface is composed of eight data bits, one address line, and three
control lines (/IORD, /IOWR, and /LCDM-CS).
The interface from the LCD controller to the LCD module is unidirectional. Data flow from
the controller chip to the LCD module. A number of control lines are provided for this func-
tion, but not all of them are used for a particular LCD module. The controller continually
reads the SRAM (which is included on the LCD controller chip used after January,2006)
for data placed there by the microprocessor and refreshes the display periodically.
Other functions support the LCD module to adjust its contrast and to turn the white LED
backlight on and off. A variable resistor between two of the LCD module’s terminals sets
the contrast. U5 is a digitally controlled potentiometer that is controlled by software. Once
the value is set, the value will be maintained. A single programmed I/O bit is used to turn
the LED backlight on or off. Since this bit does not have enough drive current to light the
LED directly, it is buffered by the FET Q1.
The controller chip used in OP7200’s sold before 2006 supported either 32K or 64K of
SRAM. These OP7200s were designed using a dual-footprint SRAM to accept either one
32K or one 128K SRAM. The 128K part was standard. The full 64K supported by the
controller is available with the 128K SRAM, plus an additional 64K can be swapped in
and out by using the programmed I/O bit VA16. Pins 1–2 on header JP9 are normally con-
nected by a 0
Ω
surface-mounted resistor, but pins 2–3 should be connected instead for
video SRAM paging with I/O bit VA16.
OP7200 units sold after January, 2006, have a new LCD controller chip because the previ-
ously used LCD controller chip is no longer available. The new LCD controller chip has
32K of internal SRAM. Figure 19 shows the area of the OP7200 that changed to accommo-
date the new LCD controller chip. The new LCD controller is not 100% code-compatible
with the old chip—Section 4.1.2.1 explains how to handle programs developed using
versions of Dynamic C before v. 9.40.
Figure 19. How to Identify Pre-2006 OP7200 Boards
D23
D20
+PWR
PWR
+K
OUT0
OUT1
OUT2
OUT3
OUT4
OUT5
OUT6
OUT7
GND
+485 GND
R44
R41
R42
R40
R31
R29
R43
R46
R45
C33
JP4
R19
R26
R27
R30
R28R25
R20
C2
R17
R16
IN16 IN17 IN18
AIN0
AIN1
AIN2
AIN3
AIN4
AIN5
AIN6
AIN7
AGND
R18
C4
R15
R1
R2
C1
JP1
D13
D12
D14
D15
Y1
C97
C104
Q5
U1
C57
D11
C36
JP2
JP7
IN0 IN1
C66
JP6
JP5
R108
C65
JP8
R61
R159
R147
Q12
J7
Q13
C39
C49
C13
L9
D24
LS1
JP10
1
3
2
4
MSTR
SLAVE
D1
D3
D2
D5
D4
Q2
R24
Q4
R23
Q3
R22
Q8
R38
Q7
R37
Q6
R39
Q1
1
R55
Q10
R56
D6
D8
D9
R64
R62
R65
C86
C29
C30
C16
C17
C18
C6
C8
C7
R91
R14
DS1
DS2
TVS1
C82
J8
R152 R151
C85
J13
J2
J6
J3
BT1
D10
R80
R81
L2 C31
C32
16
1
J14
GND
GND
GND
GND
GND
GND
GND
GND
G
ND
GND
1
JP12
JP1
1
D23
D20
+PWR
PWR
+K
OUT0
OUT1
OUT2
OUT3
OUT4
OUT5
OUT6
OUT7
GND
+485 GND
R44
R41
R42
R40
R31
R29
R43
R46
R45
C33
JP4
R19
R26
R27
R30
R28
R25
R20
C2
R17
R16
IN16 IN17 IN18
AIN0
AIN1
AIN2
AIN3
AIN4
AIN5
AIN6
AIN7
AGND
R18
C4
R15
R1
R2
C1
JP1
D13
D12
D14
D15
C5
Y1
C60
C61
Q5
U2
1
60
C57
D11
JP2
JP7
IN0 IN1
C66
JP6
JP5
R108
C65
JP8
R61
R159
R147
Q12
J7
Q13
C39
C49
C13
L9
D24
LS1
JP10
1
3
2
4
MSTR
SLAVE
D1
D3
D2
D5
D4
Q2
R24
Q4
R23
Q3
R22
Q8
R38
Q7
R37
Q6
R39
Q11
R55
Q10
R56
D6
D8
D9
R64
R62
R65
C86
C29
C30
C16
C17
C18
C6
C8
C7
R91
R14
DS1
DS2
TVS1
C82
J8
R152 R151
C85
C84
J13
J2
J6
J3
Battery
C95
C101
C60
C96
R10
C5
R1
1
C100
C61
C98
C99
C102
R80
R81
D10
C32
C31
L2
J14
Battery
PRE-2006 OP7200
CURRENT OP7200
Содержание eDisplay OP7200
Страница 1: ...eDisplay OP7200 VGA Operator Control Panel User s Manual 019 0116 060831 J...
Страница 6: ...eDisplay OP7200...
Страница 14: ...8 eDisplay OP7200...
Страница 22: ...16 eDisplay OP7200...
Страница 52: ...46 eDisplay OP7200...
Страница 126: ...120 eDisplay OP7200...
Страница 132: ...126 eDisplay OP7200...
Страница 133: ...User s Manual 127 APPENDIX A SPECIFICATIONS Appendix A provides the specifications for the OP7200...
Страница 152: ...146 eDisplay OP7200...
Страница 168: ...162 eDisplay OP7200...
Страница 172: ...166 eDisplay OP7200...
Страница 174: ......