TI TLC34058

TLC34058-110M
256 × 24 COLOR PALETTE
SGLS075 – JANUARY 1994
•
•
•
•
•
•
•
•
LinEPIC 1-µm CMOS Process
125-MHz Pipelined Architecture
Available Clock Rate . . . 110 MHz
Dual-Port Color RAM
256 Words x 24 Bits
Bit-Plane Read and Blink Masks
EIA RS-343-A Compatible Outputs
Functionally Interchangeable With
Brooktree Bt458
•
•
•
•
•
Direct Interface to SMJ340xx Graphics
Processors
Standard Microprocessor Unit (MPU)
Palette Interface
Multiplexed-TTL Pixel Ports
Triple Digital-to-Analog Converters (DACs)
Dual-Port Overlay Registers . . . 4 × 24 Bits
5-V Power Supply
description
The TLC34058-110M color-palette integrated circuit is specifically developed for high-resolution color graphics
in such applications as CAE/CAD/CAM, image processing, and video reconstruction. The architecture provides
for the display of 1280 × 1024 bit-mapped color graphics (up to eight bits per pixel resolution) with two bits of
overlay information. The TLC34058-110M has a 256-word × 24-bit RAM used as a lookup table with three 8-bit
video D/A converters.
On-chip features such as high-speed pixel clock logic minimize costly ECL interface. Multiple pixel ports and
internal multiplexing provide TTL-compatible interface (up to 32 MHz) to the frame buffer while maintaining
sophisticated color graphic data rates (up to 135 MHz). Programmable blink rates, bit plane masking and
blinking, color overlay capability, and a dual-port palette RAM are other key features. The TLC34058-110M
generates red, green, and blue signals compatible with EIA RS-343-A and can drive 75-Ω coaxial cables
terminated at each end without external buffering.
AVAILABLE OPTIONS
TA
SPEED
DAC
RESOLUTION
– 55°C to 125°C
110 MHz
8 Bits
PACKAGE
84-PIN
CERAMIC GRID ARRAY
84-PIN
QUAD FLAT PACKAGE
TLC34058-110MGA
TLC34058-110MHFG
LinEPIC is a trademark of Texas Instruments Incorporated.
Brooktree is a registered trademark of Brooktree Corporation.
Copyright  1994, Texas Instruments Incorporated
PRODUCTION DATA information is current as of publication date.
Products conform to specifications per the terms of Texas Instruments
standard warranty. Production processing does not necessarily include
testing of all parameters.
• DALLAS, TEXAS 75265
• HOUSTON, TEXAS 77251–1443
POST OFFICE BOX 655303
POST OFFICE BOX 1443
1
TLC34058-110M
256 × 24 COLOR PALETTE
SGLS075 – JANUARY 1994
!
!
#
!
"
!
!
!
#
!
"
!
!
!
!
!
02+%-* -/ $*)(,+',1
02+%-* -/ $*)(,+',1
&-1 -, 1-.
OL0A
OL0B
OL0C
OL0D
OL0E
OL1A
OL1B
OL1C
OL1D
OL1E
P0A
P0B
P0C
P0D
P0E
P1A
P1B
P1C
P1D
P1E
P2A
HFG PACKAGE
(TOP VIEW)
D0
D1
D2
D3
D4
D5
D6
D7
CE
GND
GND
VDD
C0
C1
R/W
VDD
IOR
IOG
IOB
FS ADJ
COMP
&-1 -, 1-.
21 20 19 18 17 16 15 14 13 12 11 10 9
4
8
7 6 5
3 2 1
22
84
23
83
24
82
25
81
26
80
27
79
28
78
29
77
30
76
31
75
32
74
33
73
34
72
35
71
36
70
37
69
38
68
39
67
40
66
41
65
42
64
P7E
P7D
P7C
P7B
P7A
P6E
P6D
P6C
P6B
P6A
P5E
P5D
P5C
P5B
P5A
P4E
REF
GND
VDD
GND
VDD
43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63
2
•
POST OFFICE BOX 655303 DALLAS, TEXAS 75265
POST OFFICE BOX 1443 HOUSTON, TEXAS 77251–1443
•
P2B
P2C
P2D
P2E
P3A
P3B
P3C
P3D
P3E
GND
VDD
VDD
CLK
CLK
LD
BLK
SYNC
P4A
P4B
P4C
P4D
TLC34058-110M
256 × 24 COLOR PALETTE
SGLS075 – JANUARY 1994
84-pin GA package pin assignments
SIGNAL
BLK
PIN NO.
SIGNAL
PIN NO.
L9
Port 5
M10
P5A
K11
M9
P5B
L12
CLK
L8
P5C
K12
CLK
M8
P5D
J11
P5E
SYNC
LD
Port 0
SIGNAL
PIN NO.
Power, Reference and
MPU Interface
VDD
VDD
C12
A9
J12
VDD
VDD
M7
H11
VDD
VDD
Port 6
C11
L7
P0A
G1
P6A
P0B
G2
P6B
H12
GND
B12
P0C
H1
P6C
G12
GND
B11
P0D
H2
P6D
G11
GND
M6
P0E
J
P6E
F12
GND
B6
GND
A6
Port 1
Port 7
A7
P1A
J2
P7A
F11
COMP
P1B
K1
P7B
E12
FS ADJ
B10
P1C
L1
P7C
E11
REF
C10
P1D
K2
P7D
D12
CE
A5
P1E
L2
P7E
D11
R/W
B8
Port 2
Overlay Select 0
A12
C1
A8
P2A
K3
OL0A
A1
C0
B7
P2B
M1
OL0B
C2
Data Bus
P2C
L3
OL0C
B1
D0
C3
P2D
M2
OL0D
C1
D1
B2
P2E
M3
OL0E
D2
D2
B3
D3
A2
Port 3
Overlay Select 1
P3A
L4
OL1A
D1
D4
A3
P3B
M4
OL1B
E2
D5
B4
P3C
L5
OL1C
E1
D6
A4
P3D
M5
OL1D
F1
D7
B5
P3E
L6
OL1E
F2
Port 4
DAC Current Outputs
P4A
M11
IOG
A10
P4B
L10
IOB
A11
P4C
L11
IOR
B9
P4D
K10
P4E
M12
•
POST OFFICE BOX 655303 DALLAS, TEXAS 75265
POST OFFICE BOX 1443 HOUSTON, TEXAS 77251–1443
•
3
TLC34058-110M
256 × 24 COLOR PALETTE
SGLS075 – JANUARY 1994
functional block diagram
REF
FS ADJ
CLK
CLK
Load
Control
Multiplex
Control
Reference
Amplifier
Blink
Control
COMP
LD
P0 – P7
(A – E)
40
10
OL0 – OL1
(A – E)
40
Input
Latch
10
40
Latch
10
8
8
MUX
2
Read
Mask
Blink
Mask
8
256 Words
× 24 Bits
Palette
2
RAM
4 × 24
Overlay
Palette
Registers
SYNC
BLK
CE
R/W
Bus
Control
C0
To
Control
Functions
C1
D0 – D7
8
8
8
4
Address
Register
To
Address
Control
Functions
Red
Value
Green
Value
Blue
Value
•
POST OFFICE BOX 655303 DALLAS, TEXAS 75265
POST OFFICE BOX 1443 HOUSTON, TEXAS 77251–1443
•
8
8
8-Bit
D/A
Converter
8-Bit
D/A
Converter
8-Bit
D/A
Converter
IOR
IOG
IOB
TLC34058-110M
256 × 24 COLOR PALETTE
SGLS075 – JANUARY 1994
Terminal Functions
TERMINAL
I/O
DESCRIPTION
69
I
Composite blank control input. This TTL-compatible blanking input is stored in the input latch on the rising edge
of LD. When low, BLK drives the DAC outputs to the blanking level as shown in Table 6. This causes the P0 – P7
(A – E) and OL0 – OL1 (A – E) inputs to be ignored. When high, BLK allows the device to perform in the standard
manner.
34, 35
I
Command control inputs. C0 and C1 specify the type of write or read operation (see Tables 1, 2, 3, and 4). These
TTL-compatible inputs are latched on the falling edge of CE.
CE
30
I
Chip-enable input. This TTL-compatible input control allows data to be stored and enables data to be written
or read (see Figure 1). When low, CE enables data to be written or read. When high, CE allows data to be
internally latched on the rising edge during write operations. Care should be taken to avoid transients on this
input.
CLK
72
I
Clock input. CLK provides the pixel clock rate. CLK and CLK inputs are designed to be driven by ECL logic using
a 5-V single supply.
CLK
71
I
Clock input. CLK is the complement of CLK and also provides the pixel clock rate.
COMP
42
I
Compensation input. COMP is used to compensate the internal reference amplifier (see the video generation
section). A 0.1-µF ceramic capacitor is connected between this terminal and VDD (see Figure 4). The highest
possible supply voltage rejection ratio is attained by connecting the capacitor to VDD rather than to GND.
D0 – D7
22 – 29
I
Data input bus. This TTL-compatible bus transfers data into or out of the device. The data bus is an 8-bit
bidirectional bus where D0 is the least significant bit.
FS ADJ
41
I
Full-scale adjust control input. A resistor Rset (see Figure 4), which is connected between this terminal and
GND, controls the magnitude of the full-scale video signal. The proportional current and voltage relationships
in Figure 3 are maintained independently of the full-scale output current. The relationships between Rset and
the IOR, IOG, and IOB full-scale output currents are:
Rset(Ω) = 11294 × Vref(V) / IOG(mA)
IOR, IOB (mA) = 8067 × Vref(V) / Rset(Ω)
NAME
BLK
C0, C1
NO.†
GND
31, 32,
44, 46,
75
IOR, IOG
IOB
38, 39,
40
O
Current outputs red, green, and blue. High-impedance red, green, and blue video analog current outputs can
directly drive a 75-Ω cable coaxial terminated at each end (see Figure 4).
70
I
Load-control input. This TTL-compatible load control (LD) input latches the P0 – P7 (A – E), OL0 – OL1 (A – E),
BLK, and SYNC inputs on its rising edge. The LD strobe occurs at 1/4 or 1/5 the clock rate and may be phased
independently of CLK and CLK. The LD duty cycle limits are specified in the timing requirements table.
OL0A – OL1A
OL0B – OL1B
OL0C – OL1C
OL0D – OL1D
OL0E – OL1E
12 –21
l
Overlay selection inputs. These TTL-compatible inputs for the palette-overlay registers are stored in the input
latch on the rising edge of LD. These inputs (up to 2 bits per pixel) along with bit CR6 of the command register
(refer to the command register section and Table 5) specify whether the color information is selected from the
palette RAM or the overlay registers. If the color information is selected from the overlay registers, the
OL0 – OL1 (A – E) inputs address a particular overlay register. The OL0 – OL1 (A – D) or OL0 – OL1 (A – E) inputs
are simultaneously input to the device (see the description of bit CR7 in the command register section). The
OL0 – OL1 (A) inputs are processed first, then the OL0 – OL1 (B) inputs, and so on. When obtaining the color
information from the overlay registers, the P0 – P7 (A – E) inputs are ignored. Unused inputs should be
connected to GND.
P0A – P7A
P0B – P7B
P0C – P7C
P0D – P7D
P0E – P7E
1 – 11,
48 – 67,
76 – 84
l
Address inputs. These TTL-compatible inputs for the palette RAM are stored in the input latch on the rising edge
of LD. These address inputs (up to 8 bits per pixel) select one of 256 24-bit words in the palette RAM, which
is subsequently input to the red, green, and blue D/A converters as three 8-bit or 4-bit bytes. Four or five
addresses are simultaneously input to the P0 – P7 (A – D) or P0 – P7 (A – E) ports, respectively (see the
description of bit CR7 in the command register section). The word addressed by P0A – P7A is first sent to the
DACs, then the word addressed by P0B – P7B, and so on. Unused inputs should be connected to GND.
43
I
LD
REF
Ground. All GND terminals must be connected together.
Reference voltage input. Voltage of 1.235 V is supplied at this input. An external voltage reference circuit,
shown in Figure 4, is suggested. Generating the reference voltage with a resistor network is not recommended
since low-frequency power supply noise directly couples into the DAC output signals. This input must be
decoupled by connecting a 0.1-µF ceramic capacitor between Vref and GND.
† Terminal numbers shown are for the HFG package only. For the GA package terminal assignments, see page 3.
•
POST OFFICE BOX 655303 DALLAS, TEXAS 75265
POST OFFICE BOX 1443 HOUSTON, TEXAS 77251–1443
•
5
TLC34058-110M
256 × 24 COLOR PALETTE
SGLS075 – JANUARY 1994
Terminal Functions (Continued)
TERMINAL
NAME
NO.†
I/O
DESCRIPTION
R/W
36
I
Read/write input. This TTL-compatible control input is latched on the falling edge of CE (see Figure 1). When
low, R/W writes data to the device. Data is internally latched on the rising edge of CE. When high, R/W reads
data from the device.
SYNC
68
I
Composite sync control input. This TTL-compatible SYNC input is stored in the input latch on the rising edge
of LD. When low, SYNC turns off a 40 IRE current source on the IOG output (see Figure 3). This input does
not override any control data input (see Table 6). It should be brought low during the blanking interval only (see
Figure 3). When high, SYNC allows the device to perform in the standard manner.
VDD
33, 37,
45, 47,
73, 74
Supply voltage. All VDD terminals must be connected together.
† Terminal numbers shown are for the HFG package only. For the GA package terminal assignments, see page 3.
absolute maximum ratings over operating free-air temperature (unless otherwise noted)†
Supply voltage, VDD (see Note 1) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 V
Voltage range on any digital input (see Note 1) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . – 5 V to VDD + 0.5 V
Analog output short-circuit current to any power supply or common, IOS . . . . . . . . . . . . . . . . . . . . . . unlimited
Operating free-air temperature range, TA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . – 55°C to 125°C
Storage temperature range . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . – 65°C to 150°C
Lead temperature 1,6 mm (1/16 inch) from case for 10 seconds . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 260°C
† Stresses beyond those listed under absolute maximum ratings may cause permanent damage to the device. This is a stress rating only, and
functional operation of the device at these or any other conditions beyond those indicated in the recommended operating conditions section of
this specification is not implied. Exposure to absolute-maximum-rated conditions for extended periods may affect device reliability.
NOTE 1: All voltage values are with respect to GND.
recommended operating conditions
Supply voltage, VDD
High-level Input voltage
voltage, VIH
Low-level Input voltage
voltage, VIL
CLK, CLK
MIN
NOM
4.5
5
MAX
5.5
UNIT
V
VDD – 1
2
VDD + 0.5
VDD + 0.5
V
CLK, CLK
– 0.5
– 0.5
VDD – 1.6
0.8
V
Other inputs
Other inputs
Reference voltage, Vref
1.2
1.235
1.26
V
V
V
Output load resistance, RL
37.5
Ω
FS ADJ resistor, Rset
523
Ω
Operating free-air temperature, TA
6
– 55
•
POST OFFICE BOX 655303 DALLAS, TEXAS 75265
POST OFFICE BOX 1443 HOUSTON, TEXAS 77251–1443
•
125
°C
TLC34058-110M
256 × 24 COLOR PALETTE
SGLS075 – JANUARY 1994
electrical characteristics over recommended ranges of supply voltage and operating free-air
temperature, Rset = 523 Ω, Vref = 1.235 V (unless otherwise noted)
PARAMETER
Iref
TEST CONDITIONS
MIN
Input reference current
kSVR
Supply voltage rejection ratio
f = 1 kHZ,
See Figure 4
IDD
Supply current
VDD = 5 V,
VDD = 5.5 V,
IIH
High-level input current
IIL
Low-level input current
Ci
Input capacitance, digital
f = 1 MHz,
Ci(CLK)
Input capacitance, CLK, CLK
f = 1 MHz,
VOH
VOL
High-level output voltage, D0 – D7
IOH = – 800 µA
IOL = 6.4 mA
IOZ
zo
High-impedance-state output current
CLK, CLK
Other inputs
CLK, CLK
Other inputs
Low-level output voltage, D0 – D7
C8 = 0.1 µF,
TA = 20°C
TA = – 55°C
TYP†
MAX
UNIT
10
µA
0.5
%
%∆VDD
195
550
mA
VI = VCC
VI = 2.4 V
10
µA
10
µA
VI = 0 V
VI = 0.8 V
– 10
µA
– 10
µA
4
20*
pF
4
20*
pF
VI(PP) = 1 V
VI(PP) = 1 V
2.4
V
0.4
10
Output impedance
50
Co
Output capacitance (f = 1 MHz, IO = 0)
* On products compliant to MIL-STD-883, Class B, this parameter is not production tested.
† All typical values are at TA = 25°C.
13
V
µA
kΩ
20*
pF
timing requirements over recommended ranges of supply voltage and operating free-air
temperature, Rset = 523 Ω, Vref = 1.235 V (see Note 2)
MIN
Clock frequency
LD frequency
tsu1
tsu2
Setup time, R/W, C0, C1 high before CE↓
tsu3
th1
Setup time, pixel and control
th2
th3
tw1
tw2
tw3
tw4
tw5
tw6
MAX
UNIT
110
MHz
27.5
MHz
0
ns
35
ns
3
ns
15
ns
Hold time, write data after CE↑
3
ns
Hold time, pixel and control
2
ns
Pulse duration, CE low
50
ns
Pulse duration, CE high
25
ns
Pulse duration, CLK high
4
ns
Pulse duration, CLK low
4
ns
Pulse duration, LD high
15
ns
Pulse duration, LD low
15
ns
Setup time, write data before CE↑
Hold time, R/W, C0, C1 high after CE↓
tc1
Clock cycle time
9.09
ns
tc2
LD cycle time
36.36
ns
† See Figures 1 and 2.
NOTE 2: TTL input signals are 0 to 3 V with less than 3 ns rise/fall times between 10% and 90% levels. ECL input signals are VDD – 1.8 V to
VDD – 0.8 V with less than 2 ns rise/fall times between 20% and 80% levels. For input and output signals, timing reference points are
at the 50% signal level. Analog output loads are less than 10 pF. D0 – D7 output loads are less than 40 pF.
•
POST OFFICE BOX 655303 DALLAS, TEXAS 75265
POST OFFICE BOX 1443 HOUSTON, TEXAS 77251–1443
•
7
TLC34058-110M
256 × 24 COLOR PALETTE
SGLS075 – JANUARY 1994
operating characteristics over recommended ranges of supply voltage and operating free-air
temperature, Rset = 523 Ω, Vref = 1.235 V (unless otherwise noted)
analog outputs
PARAMETER
EL
ED
MIN
TYP†
MAX
UNIT
Integral linearity error (each DAC)
±1
LSB
Differential linearity error
±1
LSB
± 5%
Gray-scale error
IO
O
Output
current
White level relative to blank
17.69
19.05
20.4
White level relative to black
16.74
17.62
18.5
Black level relative to blank
0.95
1.44
1.9
mA
A
Blank level on IOR, IOB
– 10
5
50
µA
Blank level on IOG
6.29
7.6
8.96
mA
Sync level on IOG
– 10
5
50
µA
LSB size
µA
69.1
DAC to DAC matching
2%
Output compliance voltage
† All typical values are at TA = 25°C.
–1
5%
1.2
V
switching characteristics over recommended ranges of supply voltage and operating free-air
temperature, Rset = 523 Ω, Vref = 1.235 V (see Note 2)
PARAMETER
ten1
ten2
CE low to data bus enabled
tdis
td
CE high to data bus disabled
tt
ts
MIN
TYP
MAX
10
ns
CE low to data valid
Analog output delay time (see Note 3)
UNIT
75
ns
15
ns
10
ns
Analog output transition time (see Note 4)
2
ns
Analog output settling time (see Note 5)
9
ns
50
pV-s
Glitch impulse (see Note 6)
0
Analog output skew
2
Pipeline delay
6
10
ns
clock
cycles
NOTES: 2. TTL input signals are 0 to 3 V with less than 3 ns rise/fall times between 10% and 90% levels. ECL input signals are VDD – 1.8 V
to VDD – 0.8 V with less than 2 ns rise/fall times between 20% and 80% levels. For input and output signals, timing reference points
are at the 50% signal level. Analog output loads are less than 10 pF. D0 – D7 output loads are less than 40 pF.
3. Measured from 50% point of rising clock edge to 50% point of full-scale transition
4. Measured between 10% and 90% of full-scale transition
5. Measured from 50% point of full-scale transition to output settling within ± 1 6. Glitch impulse includes clock and data feedthrough. The – 3-dB test bandwidth is twice the clock rate.
8
•
POST OFFICE BOX 655303 DALLAS, TEXAS 75265
POST OFFICE BOX 1443 HOUSTON, TEXAS 77251–1443
•
TLC34058-110M
256 × 24 COLOR PALETTE
SGLS075 – JANUARY 1994
PARAMETER MEASUREMENT INFORMATION
ÉÉÉ
ÉÉÉ
R/W, C0, C1
th1
ÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉ
ÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉ
tsu1
tw1
CE
50%
50%
ÉÉÉ
ÉÉÉ
ÉÉÉÉÉÉÉÉÉÉ
ÉÉÉÉÉÉÉÉÉÉ
ÉÉÉÉÉÉÉÉÉÉ
50%
tw2
ten2
tdis
ten1
D0 – D7 (read)
D0 – D7 (write)
ÉÉÉÉÉÉÉÉÉÉÉ
ÉÉÉÉÉÉÉÉÉÉÉ
ÉÉÉÉÉÉÉÉÉÉÉ
tsu2
th2
Figure 1. Read/Write Timing Waveform
tc2
tw5
tw6
ÉÉÉÉÉ
ÉÉÉÉÉ
ÉÉÉÉÉ
LD
P0 – P7 (A – B),
OL0 – OL1 (A – B),
SYNC, BLK
50%
50%
50%
Data
tsu3
ÉÉÉÉÉÉÉ
ÉÉÉÉÉÉ
ÉÉÉÉÉÉ
ÉÉÉÉÉÉÉ
ÉÉÉÉÉÉ
ÉÉÉÉÉÉ
ÉÉÉÉÉÉÉ
ÉÉÉÉÉÉ
ÉÉÉÉÉÉ
50%
50%
td
th3
ts
90%
50%
10%
IOR, IOG, IOB
tt
tc1
tw3
CLK
50%
50%
50%
tw4
Figure 2. Video Input /Output Timing Waveform
•
POST OFFICE BOX 655303 DALLAS, TEXAS 75265
POST OFFICE BOX 1443 HOUSTON, TEXAS 77251–1443
•
9
TLC34058-110M
256 × 24 COLOR PALETTE
SGLS075 – JANUARY 1994
PARAMETER MEASUREMENT INFORMATION
RED/BLUE
mA
19.05
GREEN
V
mA
V
White Level
0.714 26.67 1.000
92.5 IRE
1.44
0.054
Black Level
9.05 0.340
7.5 IRE
0.00
0.000
Blank Level
7.62 0.286
40 IRE
0.00
Sync Level
0.00
NOTE: The IRE (Institute of Radio Engineers – now IEEE) scale is used for defining the relative voltage levels of the sync, white, black, and blank
levels in a monitor circuit. The reference white level is set at 100 IRE units. The blanking level is set at φ IRE units. One IRE unit is equivalent
to 1/100 of the difference between the reference white level and the blanking level.
Figure 3. Composite Video Output Waveforms
COMP
C8
L1
VDD
5 V (VDD)
C5 – C7
C2 – C4
R4
REF
C10
TLC34058
C9
GND
GND
Rset
R1
R2
R3
FS ADJ
IOR
IOG
IOB
LOCATION
C1
Z1
To
Video
Connector
DESCRIPTION
VENDOR PART NUMBER
C1 – C4, C8, C9
0.1-µF ceramic capacitor
Erie RPE112Z5U104M50V
C5 – C7
0.01-µF ceramic chip capacitor
AVX 12102T903QA1018
C10
33-µF tantalum capacitor
Mallory CSR13-K336KM
L1
ferrite bead
Fair-Rite 2743001111
R1, R2, R3
75-Ω 1% metal film resistor
Dale CMF-55C
R4
1000-Ω 1% metal film resistor
Dale CMF-55C
Rset
523-Ω 1% metal film resistor
Dale CMF-55C
Z1
1.2-V diode
ā
ā
National Semiconductor
LM385Z-1.2
NOTE: The above listed vendor numbers are listed only as a guide. Substitution of devices with
similar characteristics does not degrade the performance of the TLC34058.
Figure 4. Circuit Diagram
10
•
POST OFFICE BOX 655303 DALLAS, TEXAS 75265
POST OFFICE BOX 1443 HOUSTON, TEXAS 77251–1443
•
TLC34058-110M
256 × 24 COLOR PALETTE
SGLS075 – JANUARY 1994
PARAMETER MEASUREMENT INFORMATION
5V
220 Ω
5V
CLK
CLK
5V
Monitor
Products
970E
330 Ω
220 Ω
CLK
CLK
Clock
Generator
330 Ω
TLC34058
LDA
LD
5V
0.1 µF
Vref
REF
1 kΩ
Figure 5. Generating the Clock, Load, and Voltage-Reference Signals
VDD
G0 – G7
∼ 15 PF
SYNC
(IOG only)
BLK
RL
C (stray + load)
Figure 6. Equivalent Circuit of the Current Output (IOG)
•
POST OFFICE BOX 655303 DALLAS, TEXAS 75265
POST OFFICE BOX 1443 HOUSTON, TEXAS 77251–1443
•
11
TLC34058-110M
256 × 24 COLOR PALETTE
SGLS075 – JANUARY 1994
APPLICATION INFORMATION
device ground plane
Use of a four-layer PC board is recommended. All the ground pins, voltage reference circuitry, power supply
bypass circuitry, analog output signals, and digital signals as well as any output amplifiers should have a
common ground plane.
device analog power plane (APP)
The device plus associated analog circuitry should have a separate analog power plane (APP) for VDD. The APP
powers the device, voltage reference circuitry, and any output amplifiers. It is connected to the overall PCB
power plane (VDD) at a single point through a ferrite bead, which should be within three inches of the device.
This connection is shown in Figure 4.
PCB power plane and PCB ground plane
The PCB power plane powers the digital circuitry. The PCB power plane and PCB ground planes should not
overlay the APP unless the plane-to-plane noise is common mode.
supply decoupling
Bypass capacitors should have the shortest possible lead lengths to reduce lead inductance. For best results,
connect a parallel combination of 0.1-µF ceramic and 0.01-µF chip capacitors from each VDD to GND. If chip
capacitors are not feasible, radial-lead ceramic capacitors may be substituted. These capacitors should be
located as close to the device as possible.
The performance of the internal power supply noise-rejection circuitry decreases with noise frequency. If a
switching power supply is used for VDD, close attention must be paid to reducing power supply noise. To reduce
such noise, power the APP with a three-terminal voltage regulator.
digital interconnect
Isolate the digital inputs from the analog outputs and other analog circuitry as much as possible. Shielding the
digital inputs reduces noise on the power and ground lines. Minimize the lengths of clock and data lines to
prevent high-frequency clock and data information from inducing noise into the analog part of the video system.
Active termination resistors for the digital inputs should be connected to the PCB power plane, not the APP.
Ensure that these digital inputs do not overlay the device ground plane.
analog signal interconnect
Minimizing the lead lengths between groups of VDD and GND minimizes inductive ringing. To minimize noise
pickup due to reflections and impedance mismatch, locate the device as close to the output connectors as
possible. The external voltage reference should also be as close to the device as possible to minimize noise
pickup. To maximize high-frequency supply voltage rejection, overlay the video output signals to the device
ground plane and not the APP.
Each analog output has a 75-Ω load resistor connected to GND for maximum performance. To minimize
reflections, the resistor connections between current output and ground should be as close to the device as
possible.
12
•
POST OFFICE BOX 655303 DALLAS, TEXAS 75265
POST OFFICE BOX 1443 HOUSTON, TEXAS 77251–1443
•
TLC34058-110M
256 × 24 COLOR PALETTE
SGLS075 – JANUARY 1994
APPLICATION INFORMATION
clock interfacing
To facilitate the generation of high-frequency clock signals, CLK and CLK are designed to accept differential
signals that can be generated with 5-V (single-supply) ECL logic. Due to noise margins of the CMOS process,
CLK and CLK must be differential signals. Connecting a single-ended clock signal to CLK and connecting CLK
to GND does not work. CLK and CLK require termination resistors (220 Ω to VDD and 330 Ω to GND) that should
be as close to the device as possible.
LD is typically generated by dividing the clock frequency by four (4:1 multiplexing) or five (5:1 multiplexing) and
translating the resulting signal to TTL levels. Since no phase relationship between the LD and CLK signals is
required, any propagation delay in LD caused by the divider circuitry does not affect device performance.
The pixel, overlay, sync, and blank data are latched on the rising edge of LD. LD may also be used as the shift
clock for the video DRAMs. In short, LD provides the fundamental timing for the video system.
The Bt438 clock generator (from Brooktree) is recommended for generating the CLK, CLK, LD, and REF
signals. It supports both 4:1 and 5:1 multiplexing. Alternately, the Bt438 can interface the device to a TTL clock.
Figure 5 illustrates the interconnection between the Bt438 and the device.
•
POST OFFICE BOX 655303 DALLAS, TEXAS 75265
POST OFFICE BOX 1443 HOUSTON, TEXAS 77251–1443
•
13
TLC34058-110M
256 × 24 COLOR PALETTE
SGLS075 – JANUARY 1994
PRINCIPLES OF OPERATION
microprocessor-unit (MPU) interface
As shown in the functional block diagram, the MPU has direct access to the internal control registers and color
overlay palettes via a standard MPU interface. Since the palette-RAM and overlay registers have dual ports,
they can be updated without affecting the display refresh process. One port is allocated for updating or reading
data and the other for display.
palette-RAM write or read
The palette-RAM location is addressed by the internal 8-bit address register (ADDR0 – ADDR7). The MPU can
either write to or read from this register. The register eliminates the need for external address multiplexers.
ADDR0– ADDR7 are updated via D0 – D7. To address the red, green, and blue part of a particular RAM location,
the internal address register is provided with two additional bits, ADDRa and ADDRb. These address bits count
modulo 3 and are reset to 0 when the MPU accesses the internal-address register.
After writing to or reading from the internal-address register, the MPU executes three write or read cycles (red,
green, and blue). The register ADDRab is incremented after each of these cycles so that the red, green, and
blue information is addressed from the correct part of the particular RAM location. During the blue write cycle,
the red, green, and blue color information is adjoined to form a 24-bit word, which is then written to the particular
RAM location. After the blue write/read cycle, the internal address register bits ADDR0 – ADDR7 are
incremented to access the next RAM location. For an entire palette-RAM write or read, the bits ADDR0 – ADDR7
are reset to 00 after accessing the FF (256) palette-RAM location.
Two additional control bits, C0 and C1, are used to differentiate the palette-RAM read/write function from other
operations that utilize the internal-address register. C0 and C1 are respectively set high and low for writing to
or reading from the palette RAM. Table 1 summarizes this differentiation, along with other internaladdress-register operations. C0 and C1 are each set low for writing to or reading from the internal-address
register.
14
•
POST OFFICE BOX 655303 DALLAS, TEXAS 75265
POST OFFICE BOX 1443 HOUSTON, TEXAS 77251–1443
•
TLC34058-110M
256 × 24 COLOR PALETTE
SGLS075 – JANUARY 1994
PRINCIPLES OF OPERATION
Table 1. Writing to or Reading From Palette RAM
R/W
C1
C0
ADDRb
ADDRa
L
L
L
X
X
Write ADDR0–ADDR7: D0 – D7 → ADDR0 – ADDR7; 0 → ADDRa,b
L
L
H
L
L
Write red color: D0 – D7 → RREG; increment ADDRa,b
L
L
H
L
H
Write green color: D0 – D7 → GREG; increment ADDRa,b
L
L
H
H
L
Write blue color: D0 – D7 → BREG; increment ADDRa,b; increment ADDR0 – ADDR7; write
palette RAM
H
L
L
X
X
Read ADDR0 –ADDR 7: ADDR0 – ADDR7 → D0 – D7; 0 → ADDRa,b
H
L
H
L
L
Read red color: R0 – R7 → D0 – D7; increment ADDRa,b
H
L
H
L
H
Read green color: G0 – G7 → D0 – D7; increment ADDRa,b
H
L
H
H
L
Read blue color: B0 – B7 → D0 – D7; increment ADDRa,b; increment ADDR0 – ADDR7
FUNCTION
ā
ā
ā
ā
ā
ā
X = irrelevant
overlay-register write/read
With a few exceptions, the overlay-register operation is identical to the palette-RAM write/read operation (refer
to the palette-RAM write/read section). Upon writing to or reading from the internal-address register, the
additional-address register ADDRab is automatically reset to 0. ADDRab counts modulo 3 as the red, green,
and blue information is written to or read from a particular overlay register. The four overlay registers are
addressed with internal-address-register values 00 – 03. After writing/reading blue information, the
internal-address register bits ADDR0 – ADDR7 are incremented to the next overlay location. After accessing
overlay register value 03, the internal address register does not reset to 00 but is advanced to 04.
For writing to or reading from the internal-address register, C0 and C1 are set low. When accessing the overlay
registers, C0 and C1 are set high. Refer to Table 2 for a quick reference.
Table 2. Writing to or Reading From Overlay Registers
R/W
C1
C0
ADDRb
ADDRa
L
L
L
X
X
Write ADDR0 – ADDR7: D0 – D7 → ADDR0–7; 0 → ADDRa,b
L
H
H
L
L
Write red color: D0 – D7 → RREG; increment ADDRa,b
L
H
H
L
H
Write green color: D0 – D7 → GREG; increment ADDRa,b
L
H
H
H
L
Write blue color: D0 – D7 → BREG; increment ADDRa,b; increment ADDR0 – ADDR7; write
overlay register
FUNCTION
H
L
L
X
X
Read ADDR0 – ADDR7: ADDR0 – ADDR7 → D0 – D7; 0 → ADDRa,b
H
H
H
L
L
Read red color: R0 – R7 → D0 – D7; increment ADDRa,b
H
H
H
L
H
Read green color: G0 – G7 → D0 – D7; increment ADDRa,b
H
H
H
H
L
Read blue color: B0 – B7 → D0 – D7; increment ADDRa
ADDRa,b;
b; increment ADDR0 – ADDR7
X = irrelevant
•
POST OFFICE BOX 655303 DALLAS, TEXAS 75265
POST OFFICE BOX 1443 HOUSTON, TEXAS 77251–1443
•
15
TLC34058-110M
256 × 24 COLOR PALETTE
SGLS075 – JANUARY 1994
PRINCIPLES OF OPERATION
control-register write/read
The four control registers are addressed with internal-address-register values 04 – 07. On writing to or reading
from the internal-address register, the additional address bits ADDRab are automatically reset to 0. To facilitate
read-modify-write operations, the internal-address register does not increment after writing to or reading from
the control registers. All control registers may be accessed at any time. When accessing the control registers,
C0 and C1 are respectively set low and high. Refer to Table 3 for a quick reference.
Table 3. Writing to or Reading From Control Registers
R/W
C1
C0
ADDRba
ADDRab
FUNCTION
L
L
L
X
X
Write ADDR0 – ADDR7: D0 – D7 → ADDR0 – ADDR7; 0 → ADDRa,b
L
H
L
L
L
Write control register: D0 – D7 → control register
H
L
L
X
X
Read ADDR0 – ADDR7: ADDR0 – ADDR7 → D0 – D7; 0 → ADDRa,b
H
H
L
L
L
Read control register: control register → D0 – D7
X = irrelevant
summary of internal-address-register operations
Table 4 provides a summary of operations that use the internal-address register. Figure 1 presents the read/write
timing for the device. If an invalid address is loaded into the internal-address register, the device ignores
subsequent data from the MPU during a write operation and sends incorrect data to the MPU during a read
operation.
Table 4. Internal-Address-Register Operations
INTERNAL-ADDRESSINTERNAL
ADDRESS
REGISTER VALUE
(ADDR0 – ADDR7) (HEX)
00 – FF
00 – 03
C1
L
H
C0
MPU ACCESS
H
Color-palette RAM
H
Over color 0 to 3
04
H
L
Read-mask register
05
H
L
Blink-mask register
06
H
L
Command register
07
H
L
Test register
ADDRab
(
(COUNTS
MODULO 3)
COLOR
00
Red value
01
Green value
11
Blue value
00
Red value
01
Green value
110
Blue value
interruption of display-refresh pixel data (via simultaneous pixel-data retrieval and MPU write)
If the MPU is writing to a particular palette-RAM location or overlay register (during the blue cycle) and the
display-refresh process is accessing pixel data from the same RAM location or overlay register, one or more
pixels on the display screen may be disturbed. If the MPU write data is valid during the complete chip-enable
period, a maximum of one pixel is disturbed.
16
•
POST OFFICE BOX 655303 DALLAS, TEXAS 75265
POST OFFICE BOX 1443 HOUSTON, TEXAS 77251–1443
•
TLC34058-110M
256 × 24 COLOR PALETTE
SGLS075 – JANUARY 1994
PRINCIPLES OF OPERATION
frame-buffer interface and timing
An internal latch and multiplexer enables the frame buffer to send the pixel data to the device at TTL rates. On
the rising edges of LD, information for four or five consecutive pixels is latched into the device. This information
includes the palette-RAM address (up to 8 bits), the overlay-register address (up to 2 bits), and the sync and
blank information for each of the four or five consecutive pixels. The timing diagram for this pixel-data input
transfer is shown in Figure 2, along with the video output waveforms (IOR, IOG, and IOB). With this architecture,
the sync and blank timing can only be recognized with four- or five-pixel resolution.
The display-refresh process follows the first-in first-out format. Color data is output from the device in the same
order in which palette RAM and overlay addresses are input. This process continues until all four or five pixels
have been output, at which point the cycle repeats.
The overlay timing can be controlled by the pixel timing; however, this approach requires that the frame buffer
emit additional bit planes to control the overlay selection on a pixel basis. Alternately, the overlay timing can be
controlled by external-character or cursor-generation timing (see the color selection section).
No phase relationship between the LD and CLK signals is required (see Figure 2). Therefore, the LD signal can
be derived by externally dividing the CLK signal by four or five. Any propagation delay in LD caused by the divider
circuitry does not render the device nonfunctional. Regardless of the phase relationship between LD and CLK,
the pixel, overlay, sync, and blank data are latched on the rising edge of LD.
The device has an internal load signal (not brought out to a pin) that is synchronous to CLK and follows LD by
at least one and not more than four clock cycles. This internal load signal transfers the LD-latched data into a
second set of latches, which are then internally multiplexed at the pixel clock or CLK signal frequency.
For 4:1 or 5:1 multiplexing, a rising edge of LD should occur every four or five clock cycles. Otherwise, the
internal load signal generation circuitry cannot lock onto or synchronize with LD.
color selection
The read mask, blink mask, and command registers process eight bits of color information (P0 – P7) and two
bits of overlay information (OL0 – OL1) for each pixel every clock cycle. Control registers allow individual bit
planes to be enabled/disabled for display and/or blinked at one of four blink rates and duty cycles (see the
command register section, bits CR4 – CR5).
By monitoring the BLK input to determine vertical retrace intervals, the device ensures that a color change due
to blinking occurs only during the nonactive display time. A color change does not occur in the middle of the
screen. A vertical retrace is sensed when BLK is low for at least 256 LD cycles. The color information is then
selected from the palette RAM or overlay registers in accordance with the processed input pixel data.
Table 5 presents the effect of the processed input pixel data upon color selection. P0 is the least significant bit
(LSB) of the color-palette RAM. When CR6 is high and both OL1 and OL0 are low, color information resides in
the color-palette RAM. When CR6 is low or either of the overlay inputs is high, the overlay registers provide the
DAC inputs.
•
POST OFFICE BOX 655303 DALLAS, TEXAS 75265
POST OFFICE BOX 1443 HOUSTON, TEXAS 77251–1443
•
17
TLC34058-110M
256 × 24 COLOR PALETTE
SGLS075 – JANUARY 1994
PRINCIPLES OF OPERATION
Table 5. Input Pixel Data Versus Color Selection
COMMAND
COMMANDREGISTER
BIT
OVERLAY
OVERLAYSELECT
INPUT
COLOR
ADDRESS
(HEX)
COLOR
INFORMATION
CR6
OL1
OL0
P7 – P0
H
L
L
00
Color palette entry 00
H
L
L
01
Color palette entry 01
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
H
L
L
FF
Color palette entry FF
L
L
L
XX
Overlay register 0
X
L
H
XX
Overlay register 1
X
H
L
XX
Overlay register 2
X
H
H
XX
Overlay register 3
X = irrelevant
video generation
The TLC34058 presents eight bits of red, green, and blue information from either the palette RAM or overlay
registers to the three 8-bit DACs during every clock cycle. The DAC outputs produce currents that correlate to
their respective color input data. These output currents are translated to voltage levels that drive the color CRT
monitor. The SYNC and BLK signals adjust the DAC analog output currents to generate specific output levels
that are required in video applications. Table 6 shows the effect of SYNC and BLK upon the DAC output currents.
Figure 3 presents the overall composite video output waveforms. Only the green output (IOG) contains sync
information.
The DAC architecture ensures monotonicity and reduced switching transients by using identical current sources
and routing their outputs to the DAC current output or GND. Utilizing identical current sources eliminates the
need for precision component ratios within the DAC ladder circuitry. An on-chip operational amplifier stabilizes
the DAC full-scale output current over temperature and power supply variations.
Table 6. Effects of SYNC and BLK Upon DAC Output Currents (see Note 7)
DESCRIPTION
IOG
(mA)
IOR,, IOB
(mA)
SYNC
BLK
DAC
INPUTS
White
26.67
19.05
H
H
FF
Data
data + 9.05
data + 1.44
H
H
data
Data w/o SYNC
data + 1.44
data + 1.44
L
H
data
Black
9.05
1.44
H
H
00
Black w/o SYNC
1.44
1.44
L
H
00
Black
7.62
0
H
L
xx
SYNC
0
0
L
L
xx
NOTE 7: The data in this table is measured with full-scale IOG current = 26.67 mA, Rset = 523 Ω,
Vref = 1.235 V.
command register
The MPU can write to or read from the command register at any time. The command register is not initialized.
CR0 corresponds to the D0 data bus line. Refer to Table 7 for a quick reference.
18
•
POST OFFICE BOX 655303 DALLAS, TEXAS 75265
POST OFFICE BOX 1443 HOUSTON, TEXAS 77251–1443
•
TLC34058-110M
256 × 24 COLOR PALETTE
SGLS075 – JANUARY 1994
PRINCIPLES OF OPERATION
Table 7. Command Register
COMMANDREGISTER
BIT
COMMAND-REGISTER
BIT FUNCTION
COMMAND-REGISTER BIT DESCRIPTION
CR7
Multiplex-select bit
low: selects 4:1 multiplexing
high: selects 5:1 multiplexing
This bit selects either 4:1 or 5:1 multiplexing for the palette RAM and overlay-register address,
SYNC, and BLK inputs. If 4:1 multiplexing is selected, the device ignores the E palette RAM and
overlay-register-address inputs
inputs. These inputs should be connected to GND,
GND and the LD signal
frequency should be 1/4 of the clock frequency. If 5:1 is specified, all of the palette RAM and
overlay-register-address inputs are used and the LD signal should be 1/5 of the clock frequency.
CR6
RAM-enable bit
low: use overlay register 0
high: use palette RAM
When the overlay select bits (OL0 and OL1) are both low, this bit causes the DACs color
information to be selected from overlay register 0 or the palette RAM.
CR5, CR4
Blink-rate-select bits
00: 16 on, 48 off (25/75)
01: 16 on, 16 off (50/50)
10: 32 on, 32 off (50/50)
These two bits select the blink-rate cycle time and duty cycle. The on and off numbers specify
the blink-rate cycle time as the number of vertical periods. The numbers in parentheses specify
the duty cycle in (on/off) percent.
CR3
OL1 blink-enable bit
low: disable blinking
high: enable blinking
If this bit is a high, the OL1 (A – E) inputs toggle between a logic 0 and their input value at the
selected blink rate before latching the incoming pixel data. Simultaneously, command-register
CR1 must be set high. If the CR2 bit is low, the OL0 (A – E) inputs are unaffected.
CR2
OL0 blink-enable bit
low: disable blinking
high: enable blinking
If this bit is high, the OL0 (A – E) inputs toggle between a logic 0 and their input value at the
selected blink rate before latching the incoming pixel data. Simultaneously, command-register
CR0 must be set high. If the CR2 bit is low, the OL0 (A – E) inputs are unaffected.
CR1
OL1 display-enable bit
low: disable
high: enable
If this bit is low, the OL1 (A – E) inputs are forced to a logic 0 before latching the incoming pixel
data. If the CR1 bit is high, the OL1 (A – E) inputs are affected.
CR0
OL0 display-enable bit
low: disable
high: enable
If this bit is low, the OL0 (A – E) inputs are forced to a logic 0 before latching the incoming pixel
data. If the CR0 bit is high, the OL0 (A – E) inputs are affected.
read-mask register
The read-mask register is used to enable (high) or disable (low) the eight bit planes (P0 – P7) within the
palette-RAM addresses. The enabling or disabling is accomplished by logic ANDing the read-mask register with
the palette-RAM address before addressing the palette RAM. Read-mask register bit 0 corresponds to data-bus
line D0. The MPU can write to or read from this register at any time. This register is not initialized.
blink-mask register
The blink-mask register is used to enable (high) or disable (low) the blinking of bit planes within the palette-RAM
addresses. For example, if blink-mask register bit n is set high, the true Pn value addresses the palette RAM
during the on portion of the blink cycle. During the off part of the blink cycle, the Pn value is replaced with a 0
before the palette RAM is addressed. The blink-rate cycle time and duty cycle is specified by command-register
bits CR4 and CR5. If blink-mask-register bit n is set low, the true Pn value always addresses the palette RAM.
Blink-mask-register bit 0 corresponds to data-bus line D0. This register is not initialized.
•
POST OFFICE BOX 655303 DALLAS, TEXAS 75265
POST OFFICE BOX 1443 HOUSTON, TEXAS 77251–1443
•
19
TLC34058-110M
256 × 24 COLOR PALETTE
SGLS075 – JANUARY 1994
PRINCIPLES OF OPERATION
test register
The test register allows the MPU to read the inputs to the DAC for diagnostic purposes. The MPU can write to
or read from this register at any time. This register is not initialized. Only the four least significant bits can be
written to, while all eight bits can be read. Test-register bit 0 corresponds to data-bus line D0. A function
description of this register is presented in Table 8.
Table 8. Functional Description of Test Register
TR3 – TR0
D4 – D7
FUNCTION
0100
4 MSBs of blue data input
0010
4 MSBs of green data input
0001
4 MSBs of red data input
1100
4 LSBs of blue data input
1010
4 LSBs of green data input
1001
4 LSBs of red data input
MPU read
d or write
i D0 – D3
MPU read
d D0 – D7
To read the DAC inputs, the MPU must first load the test register four least significant bits. One of the test register
bits, b0 (red DAC), b1 (green DAC), or b2 (blue DAC), must be set high and the other two bits low. This process
determines whether the inputs to the red, green, or blue DAC are read. The test register bit b3 must be set high
for reading the four most significant DAC inputs or low for reading the four least significant inputs. The MPU then
reads the test register while the test register’s four least significant bits contain the previously written information.
Either the device clock must be slowed down to the MPU cycle time or the same pixel and overlay data must
be continuously presented to the device during the entire MPU read cycle.
20
Printed
in U.S.A.
•
POST OFFICE BOX 655303 DALLAS, TEXAS 75265
POST OFFICE BOX 1443 HOUSTON, TEXAS 77251–1443
•
SGLS075
IMPORTANT NOTICE
Texas Instruments (TI) reserves the right to make changes to its products or to discontinue any semiconductor
product or service without notice, and advises its customers to obtain the latest version of relevant information
to verify, before placing orders, that the information being relied on is current.
TI warrants performance of its semiconductor products and related software to the specifications applicable at
the time of sale in accordance with TI’s standard warranty. Testing and other quality control techniques are
utilized to the extent TI deems necessary to support this warranty. Specific testing of all parameters of each
device is not necessarily performed, except those mandated by government requirements.
Certain applications using semiconductor products may involve potential risks of death, personal injury, or
severe property or environmental damage (“Critical Applications”).
TI SEMICONDUCTOR PRODUCTS ARE NOT DESIGNED, INTENDED, AUTHORIZED, OR WARRANTED
TO BE SUITABLE FOR USE IN LIFE-SUPPORT APPLICATIONS, DEVICES OR SYSTEMS OR OTHER
CRITICAL APPLICATIONS.
Inclusion of TI products in such applications is understood to be fully at the risk of the customer. Use of TI
products in such applications requires the written approval of an appropriate TI officer. Questions concerning
potential risk applications should be directed to TI through a local SC sales office.
In order to minimize risks associated with the customer’s applications, adequate design and operating
safeguards should be provided by the customer to minimize inherent or procedural hazards.
TI assumes no liability for applications assistance, customer product design, software performance, or
infringement of patents or services described herein. Nor does TI warrant or represent that any license, either
express or implied, is granted under any patent right, copyright, mask work right, or other intellectual property
right of TI covering or relating to any combination, machine, or process in which such semiconductor products
or services might be or are used.
Copyright  1996, Texas Instruments Incorporated