FAIRCHILD 74ACT715

74ACT715, 74ACT715-R
Programmable Video Sync Generator
tm
Features
General Description
■ Maximum Input Clock Frequency > 130MHz
The ACT715 and ACT715-R are 20-pin TTL-input
compatible devices capable of generating Horizontal,
Vertical and Composite Sync and Blank signals for televisions and monitors. All pulse widths are completely
definable by the user. The devices are capable of generating signals for both interlaced and noninterlaced
modes of operation. Equalization and serration pulses
can be introduced into the Composite Sync signal when
needed.
■ Interlaced and non-interlaced formats available
■ Separate or composite horizontal and vertical Sync
■
■
■
■
■
and Blank signals available
Complete control of pulse width via register
programming
All inputs are TTL compatible
8mA drive on all outputs
Default RS170/NTSC values mask programmed into
registers
ACT715-R is mask programmed to default to a Clock
Enable state for easier start-up into 14.31818MHz
RS170 timing
Four additional signals can also be made available when
Composite Sync or Blank are used. These signals can
be used to generate horizontal or vertical gating pulses,
cursor position or vertical Interrupt signal.
These devices make no assumptions concerning the
system architecture. Line rate and field/frame rate are all
a function of the values programmed into the data registers, the status register, and the input clock frequency.
The ACT715 is mask programmed to default to a Clock
Disable state. Bit 10 of the Status Register, Register 0,
defaults to a logic “0”. This facilitates (re)programming
before operation.
The ACT715-R is the same as the ACT715 in all
respects except that the ACT715-R is mask programmed to default to a Clock Enabled state. Bit 10 of
the Status Register defaults to a logic “1”. Although
completely (re)programmable, the ACT715-R version is
better suited for applications using the default
14.31818MHz RS-170 register values. This feature
allows power-up directly into operation, following a single
CLEAR pulse.
Ordering Information
Package
Number
Package Description
74ACT715SC
M20B
20-Lead Small Outline Integrated Circuit (SOIC), JEDEC MS-013, 0.300" Wide
74ACT715-RSC
M20B
20-Lead Small Outline Integrated Circuit (SOIC), JEDEC MS-013, 0.300" Wide
Order Number
Device also available in Tape and Reel. Specify by appending suffix letter “X” to the ordering number.
FACT™ is a trademark of Fairchild Semiconductor Corporation.
©1988 Fairchild Semiconductor Corporation
74ACT715, 74ACT715-R Rev. 1.3
www.fairchildsemi.com
74ACT715, 74ACT715-R Programmable Video Sync Generator
April 2007
Pin Description
CLR: The CLEAR pin is an asynchronous input that initializes the device when it is HIGH. Initialization consists
of setting all registers to their mask programmed values,
and initializing all counters, comparators and registers.
The CLEAR pin has been implemented as a Schmitt
trigger for better noise immunity. A CLEAR pulse should
be asserted by the user immediately after power-up to
ensure proper initialization of the registers—even if the
user plans to (re)program the device.
There are a Total of 13 inputs and 5 outputs on the
ACT715.
Data Inputs D0–D7: The Data Input pins connect to the
Address Register and the Data Input Register.
ADDR/DATA: The ADDR/DATA signal is latched into
the device on the falling edge of the LOAD signal. The
signal determines if an address (0) or data (1) is present
on the data bus.
L/HBYTE: The L/HBYTE signal is latched into the device
on the falling edge of the LOAD signal. The signal determines if data will be read into the 8 LSB's (0) or the
4 MSB's (1) of the Data Registers. A 1 on this pin when
an ADDR/DATA is a 0 enables Auto-Load Mode.
Note: A CLEAR pulse will disable the CLOCK on the ACT715
and will enable the CLOCK on the ACT715-R.
ODD/EVEN: Output that identifies if display is in odd
(HIGH) or even (LOW) field of interlace when device is in
interlaced mode of operation. In noninterlaced mode of
operation this output is always HIGH. Data can be serially scanned out on this pin during Scan Mode.
LOAD: The LOAD control pin loads data into the
Address or Data Registers on the rising edge. ADDR/
DATA and L/HBYTE data is loaded into the device on
the falling edge of the LOAD. The LOAD pin has been
implemented as a Schmitt trigger input for better noise
immunity.
VCSYNC: Outputs Vertical or Composite Sync signal
based on value of the Status Register. Equalization and
Serration pulses will (if enabled) be output on the
VCSYNC signal in composite mode only.
CLOCK: System CLOCK input from which all timing is
derived. The clock pin has been implemented as a
Schmitt trigger for better noise immunity. The CLOCK
and the LOAD signal are asynchronous and independent. Output state changes occur on the falling edge of
CLOCK.
VCBLANK: Outputs Vertical or Composite Blanking
signal based on value of the Status Register.
HBLHDR: Outputs Horizontal Blanking signal, Horizontal Gating signal or Cursor Position based on value of
the Status Register.
HSYNVDR: Outputs Horizontal Sync signal, Vertical
Gating signal or Vertical Interrupt signal based on value
of Status Register.
©1988 Fairchild Semiconductor Corporation
74ACT715, 74ACT715-R Rev. 1.3
www.fairchildsemi.com
2
74ACT715, 74ACT715-R Programmable Video Sync Generator
Connection Diagram
74ACT715, 74ACT715-R Programmable Video Sync Generator
Logic Block Diagram
Figure 1.
©1988 Fairchild Semiconductor Corporation
74ACT715, 74ACT715-R Rev. 1.3
www.fairchildsemi.com
3
Stresses exceeding the absolute maximum ratings may damage the device. The device may not function or be
operable above the recommended operating conditions and stressing the parts to these levels is not recommended.
In addition, extended exposure to stresses above the recommended operating conditions may affect device reliability.
The absolute maximum ratings are stress ratings only.
Symbol
VCC
IIK
Parameter
Rating
Supply Voltage
–0.5V to +7.0V
DC Input Diode Current
VI = –0.5V
–20mA
VI = VCC + 0.5V
+20mA
VI
DC Input Voltage
IOK
DC Output Diode Current
–0.5V to VCC + 0.5V
VO = –0.5V
–20mA
VO = VCC + 0.5V
+20mA
VO
DC Output Voltage
–0.5V to VCC + 0.5V
IO
DC Output Source or Sink Current
±15mA
ICC or IGND DC VCC or Ground Current per Output Pin
±20mA
TSTG
Storage Temperature
–65°C to +150°C
TJ
Junction Temperature
140°C
Recommended Operating Conditions
The Recommended Operating Conditions table defines the conditions for actual device operation. Recommended
operating conditions are specified to ensure optimal performance to the datasheet specifications. Fairchild does not
recommend exceeding them or designing to absolute maximum ratings.
Symbol
VCC
Parameter
Supply Voltage
VI
Input Voltage
VO
Output Voltage
TA
Operating Temperature
∆V / ∆t
Rating
4.5V to 5.5V
0V to VCC
0V to VCC
–40°C to +85°C
125mV/ns
Minimum Input Edge Rate:
VIN from 0.8V to 2.0V, VCC @ 4.5V, 5.5V
©1988 Fairchild Semiconductor Corporation
74ACT715, 74ACT715-R Rev. 1.3
www.fairchildsemi.com
4
74ACT715, 74ACT715-R Programmable Video Sync Generator
Absolute Maximum Ratings
All of the data registers are 12 bits wide. Width’s of all
pulses are defined by specifying the start count and end
count of all pulses. Horizontal pulses are specified with
respect to the number of clock pulses per line and vertical pulses are specified with respect to the number of
lines per frame.
Bits 9–11
REG0—Status Register
B10—
The Status Register controls the mode of operation, the
signals that are output and the polarity of these outputs.
The default value for the Status Register is 0 (000 Hex) for
the ACT715 and is “1024” (400 Hex) for the ACT715-R.
B11—
Bits 9 through 11 enable several different features of the
device.
B9—
Bits 0–2
B2 B1 B0
0 0 0
VCBLANK VCSYNC
CBLANK
CSYNC
HBLHDR HSYNVDR
HGATE
Horizontal Interval Registers
VGATE
The Horizontal Interval Registers determine the number
of clock cycles per line and the characteristics of the
Horizontal Sync and Blank pulses.
(DEFAULT)
0
0
1
VBLANK
CSYNC
HBLANK
VGATE
0
1
0
CBLANK
VSYNC
HGATE
HSYNC
0
1
1
VBLANK
VSYNC
HBLANK
HSYNC
1
0
0
CBLANK
CSYNC
CUSOR
VINT
1
0
1
VBLANK
CSYNC
HBLANK
VINT
1
1
0
CBLANK
VSYNC
CUSOR
HSYNC
1
1
1
VBLANK
VSYNC
HBLANK
HSYNC
REG1— Horizontal Front Porch
REG2— Horizontal Sync Pulse End Time
REG3— Horizontal Blanking Width
REG4— Horizontal Interval Width # of Clocks per Line
Vertical Interval Registers
The Vertical Interval Registers determine the number of
lines per frame, and the characteristics of the Vertical
Blank and Sync Pulses.
Bits 3–4
B4
B3
0
0
Mode of Operation
REG5— Vertical Front Porch
REG6— Vertical Sync Pulse End Time
REG7— Vertical Blanking Width
REG8— Vertical Interval Width # of Lines per Frame
Interlaced Double Serration and Equalization
(DEFAULT)
0
1
Non Interlaced Double Serration
1
0
Illegal State
1
1
Non Interlaced Single Serration and Equalization
Enable Equalization/Serration Pulses (0)
Disable Equalization/Serration Pulses (1)
Disable System Clock (0)
Enable System Clock (1)
Default values for B10 are “0” in the ACT715
and “1” in the ACT715-R.
Disable Counter Test Mode (0)
Enable Counter Test Mode (1)
This bit is not intended for the user but is for
internal testing only.
Equalization and Serration Pulse Specification
Registers
Double Equalization and Serration mode will output
equalization and serration pulses at twice the HSYNC
frequency (i.e., 2 equalization or serration pulses for
every HSYNC pulse). Single Equalization and Serration
mode will output an equalization or serration pulse for
every HSYNC pulse. In Interlaced mode equalization
and serration pulses will be output during the VBLANK
period of every odd and even field. Interlaced Single
Equalization and Serration mode is not possible with this
part.
These registers determine the width of equalization and
serration pulses and the vertical interval over which they
occur.
Bits 5–8
Vertical Interrupt Specification Registers
Bits 5 through 8 control the polarity of the outputs. A
value of zero in these bit locations indicates an output
pulse active LOW. A value of 1 indicates an active HIGH
pulse.
These Registers determine the width of the Vertical
Interrupt signal if used.
B5—
B6—
B7—
B8—
REG 9— Equalization Pulse Width End Time
REG10— Serration Pulse Width End Time
REG11— Equalization/Serration Pulse Vertical Interval
Start Time
REG12— Equalization/Serration Pulse Vertical Interval
End Time
REG13— Vertical Interrupt Activate Time
REG14— Vertical Interrupt Deactivate Time
VCBLANK Polarity
VCSYNC Polarity
HBLHDR Polarity
HSYNVDR Polarity
©1988 Fairchild Semiconductor Corporation
74ACT715, 74ACT715-R Rev. 1.3
www.fairchildsemi.com
5
74ACT715, 74ACT715-R Programmable Video Sync Generator
Register Description
REG15—
REG16—
REG17—
REG18—
Horizontal Cursor Position Start Time
Horizontal Cursor Position End Time
Vertical Cursor Position Start Time
Vertical Cursor Position End Time
Signal Specification
Horizontal Sync and Blank Specifications
always based on whole-lines and does not add 1 for the
first clock. The vertical counter starts at the value of 1
and counts until the value of VMAX. No restrictions exist
on the values placed in the vertical registers. Vertical
Blank will change on the leading edge of HBLANK. Vertical Sync will change on the leading edge of HSYNC.
(See Figure 3.) Vertical Frame Period (VPER) = REG(8)
× hper
All horizontal signals are defined by a start and end time.
The start and end times are specified in number of clock
cycles per line. The start of the horizontal line is considered pulse 1 not 0. All values of the horizontal timing registers are referenced to the falling edge of the Horizontal
Blank signal (See Figure 2). Since the first CLOCK edge,
CLOCK #1, causes the first falling edge of the Horizontal
Blank reference pulse, edges referenced to this first
Horizontal edge are n + 1 CLOCKs away, where “n” is
the width of the timing in question. Registers 1, 2, and 3
are programmed in this manner. The horizontal counters
start at 1 and count until HMAX. The value of HMAX
must be divisible by 2. This limitation is imposed because
during interlace operation this value is internally divided
by 2 in order to generate serration and equalization
pulses at 2 × the horizontal frequency. Horizontal signals
will change on the falling edge of the CLOCK signal.
Signal specifications are shown below.
Vertical Field Period (VPER/n) = REG(8) × hper/n
Vertical Blanking Width = [REG(7) – 1] × hper/n
Vertical Syncing Width = [REG(6) – REG(5)] × hper/n
Vertical Front Porch = [REG(5) – 1] × hper/n
where,
n = 1 for noninterlaced
n = 2 for interlaced
Composite Sync and Blank Specifications
Horizontal Period (HPER) = REG(4) × ckper
Composite Sync and Blank signals are created by logically ANDing (ORing) the active LOW (HIGH) signals of
the corresponding vertical and horizontal components of
these signals. The Composite Sync signal may also
include serration and/or equalization pulses. The Serration pulse interval occurs in place of the Vertical Sync
interval. Equalization pulses occur preceding and/or
following the Serration pulses. The width and location of
these pulses can be programmed through the registers
shown below. (See Figure 4.)
Horizontal Blanking Width = [REG(3) – 1] × ckper
Horizontal Sync Width = [REG(2) – REG(1)] × ckper
Horizontal Front Porch = [REG(1) – 1] × ckper
Vertical Sync and Blank Specifications
All vertical signals are defined in terms of number of
lines per frame. This is true in both interlaced and noninterlaced modes of operation. Care must be taken to not
specify the Vertical Registers in terms of lines per field.
Since the first CLOCK edge, CLOCK #1, causes the first
falling edge of the Vertical Blank (first Horizontal Blank)
reference pulse, edges referenced to this first edge are n
+ 1 lines away, where “n” is the width of the timing in
question. Registers 5, 6, and 7 are programmed in this
manner. Also, in the interlaced mode, vertical timing is
based on half-lines. Therefore registers 5, 6, and 7 must
contain a value twice the total horizontal (odd and even)
plus 1 (as described above). In non-interlaced mode, all
vertical timing is based on whole-lines. Register 8 is
©1988 Fairchild Semiconductor Corporation
74ACT715, 74ACT715-R Rev. 1.3
Horizontal
Equalization PW = [REG(9) – REG(1)] × ckper
REG 9 = (HFP) + (HEQP) + 1
Horizontal
Serration PW = [REG(4)/n + REG(1) – REG(10)] × ckper
REG 10 = (HFP) + (HPER/2) – (HSERR) + 1
where,
n = 1 for noninterlaced single serration/equalization
n = 2 for noninterlaced double serration/equalization
n = 2 for interlaced operation
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6
74ACT715, 74ACT715-R Programmable Video Sync Generator
CURSOR LOCATION REGISTERS
These 4 registers determine the cursor position location,
or they generate separate Horizontal and Vertical Gating
signals.
74ACT715, 74ACT715-R Programmable Video Sync Generator
Figure 2. Horizontal Wave Specification
Figure 3. Vertical Waveform Specification
Figure 4. Equalization/Serration Interval Programming
©1988 Fairchild Semiconductor Corporation
74ACT715, 74ACT715-R Rev. 1.3
www.fairchildsemi.com
7
Cursor Position and Vertical Interrupt
Horizontal Drive and Vertical Drive outputs can be utilized as general purpose Gating Signals. Horizontal and
Vertical Gating Signals are available for use when Composite Sync and Blank signals are selected and the
value of Bit 2 of the Status Register is 0. The Vertical
Gating signal will change in the same manner as that
specified for the Vertical Blank.
The Cursor Position and Vertical Interrupt signal are
available when Composite Sync and Blank signals are
selected and Bit 2 of the Status Register is set to the
value of 1. The Cursor Position generates a single pulse
of n clocks wide during every line that the cursor is specified. The signals are generated by logically ORing
(ANDing) the active LOW (HIGH) signals specified by
the registers used for generating Horizontal and Vertical
Gating signals. The Vertical Interrupt signal generates a
pulse during the vertical interval specified. The Vertical
Interrupt signal will change in the same manner as that
specified for the Vertical Blanking signal.
Horizontal
Gating
Signal Width = [REG(16) – REG(15)] × ckper
Vertical
Gating
Signal Width = [REG(18) – REG(17)] × hper
Horizontal Cursor Width = [REG(16) – REG(15)] × ckper
Vertical Cursor Width = [REG(18) – REG(17)] × hper
Vertical Interrupt Width = [REG(14) – REG(13)] × hper
Addressing Logic
Byte is written the address counter is incremented by 1.
The counter has been implemented to loop on the initial
value loaded into the address register. For example: If a
value of 0 was written into the address register then the
counter would count from 0 to 18 before resetting back
to 0. If a value of 15 was written into the address register
then the counter would count from 15 to 18 before looping back to 15. If a value greater than or equal to 18 is
placed into the address register the counter will continuously loop on this value. Auto addressing is initiated on
the falling edge of LOAD when ADDRDATA is 0 and
LHBYTE is 1. Incrementing and loading of data registers
will not commence until the falling edge of LOAD after
ADDRDATA goes to 1. The next rising edge of LOAD
will load the first byte of data. Auto Incrementing is disabled on the falling edge of LOAD after ADDRDATA and
LHBYTE goes low.
The register addressing logic is composed of two blocks
of logic. The first is the address register and counter
(ADDRCNTR), and the second is the address decode
(ADDRDEC).
ADDRCNTR Logic
Addresses for the data registers can be generated by
one of two methods. Manual addressing requires that
each byte of each register that needs to be loaded needs
to be addressed. To load both bytes of all 19 registers
would require a total of 57 load cycles (19 address and
38 data cycles). Auto Addressing requires that only the
initial register value be specified. The Auto Load
sequence would require only 39 load cycles to completely program all registers (1 address and 38 data
cycles). In the auto load sequence the low order byte of
the data register will be written first followed by the high
order byte on the next load cycle. At the time the High
©1988 Fairchild Semiconductor Corporation
74ACT715, 74ACT715-R Rev. 1.3
www.fairchildsemi.com
8
74ACT715, 74ACT715-R Programmable Video Sync Generator
Horizontal and Vertical Gating Signals
Cycle #
Load Falling Edge
Load Rising Edge
1
Enable Manual Addressing
Load Address m
2
Enable Lbyte Data Load
Load Lbyte m
3
Enable Hbyte Data Load
Load Hbyte m
4
Enable Manual Addressing
Load Address n
5
Enable Lbyte Data Load
Load Lbyte n
6
Enable Hbyte Data Load
Load Hbyte n
Auto Addressing Mode
Cycle #
Load Falling Edge
Load Rising Edge
1
Enable Auto Addressing
Load Start Address n
2
Enable Lbyte Data Load
Load Lbyte (n)
3
Enable Hbyte Data Load
Load Hbyte (n); Inc Counter
4
Enable Lbyte Data Load
Load Lbyte (n+1)
5
Enable Hbyte Data Load
Load Hbyte (n+1); Inc Counter
6
Enable Manual Addressing
Load Address
©1988 Fairchild Semiconductor Corporation
74ACT715, 74ACT715-R Rev. 1.3
www.fairchildsemi.com
9
74ACT715, 74ACT715-R Programmable Video Sync Generator
Manual Addressing Mode
ADDRDATA pin (Auto Addressing Mode) will not cause
this address to automatically increment. The address will
loop back onto itself regardless of the state of
ADDRDATA unless the address on the Data inputs has
been changed with ADDRDATA at 0.
The ADDRDEC logic decodes the current address and
generates the enable signal for the appropriate register.
The enable values for the registers and counters change
on the falling edge of LOAD. Two types of ADDRDEC
logic is enabled by 2 pair of addresses, Addresses 22 or
54 (Vectored Restart logic) and Addresses 23 or 55
(Vectored Clear logic). Loading these addresses will
enable the appropriate logic and put the part into either a
Restart (all counter registers are reinitialized with preprogrammed data) or Clear (all registers are cleared to
zero) state. Reloading the same ADDRDEC address will
not cause any change in the state of the part. The
outputs during these states are frozen and the internal
CLOCK is disabled. Clocking the part during a Vectored
Restart or Vectored Clear state will have no effect on the
part. To resume operation in the new state, or disable
the Vectored Restart or Vectored Clear state, another
non-ADDRDEC address must be loaded. Operation will
begin in the new state on the rising edge of the nonADDRDEC load pulse. It is recommended that an
unused address be loaded following an ADDRDEC operation to prevent data registers from accidentally being
corrupted. The following Addresses are used by the
device.
Address 0
Status Register REG0
Address 1–18
Data Registers REG1–REG18
Address 19–21
Unused
Address 22/54
Restart Vector (Restarts Device)
Address 23/55
Clear Vector (Zeros All Registers)
Address 24–31
Unused
Address 32–50
Register Scan Addresses
Address 51–53
Counter Scan Addresses
Address 56–63
Unused
Figure 5. ADDRDEC Timing
Gen Locking
The ACT715 and ACT715-R is designed for master
SYNC and BLANK signal generation. However, the
devices can be synchronized (slaved) to an external timing signal in a limited sense. Using Vectored Restart, the
user can reset the counting sequence to a given location, the beginning, at a given time, the rising edge of the
LOAD that removes Vector Restart. At this time the next
CLOCK pulse will be CLOCK 1 and the count will restart
at the beginning of the first odd line.
Preconditioning the part during normal operation, before
the desired synchronizing pulse, is necessary. However,
since LOAD and CLOCK are asynchronous and independent, this is possible without interruption or data and
performance corruption. If the defaulted 14.31818MHz
RS-170 values are being used, preconditioning and
restarting can be minimized by using the CLEAR pulse
instead of the Vectored Restart operation. The ACT715-R
is better suited for this application because it eliminates
the need to program a 1 into Bit 10 of the Status Register
to enable the CLOCK. Gen Locking to another count
location other than the very beginning or separate
horizontal/vertical resetting is not possible with the
ACT715 nor the ACT715-R.
At any given time only one register at most is selected. It
is possible to have no registers selected.
Vectored Restart Address
The function of addresses 22 (16H) or 54 (36H) are similar to that of the CLR pin except that the preprogramming of the registers is not affected. It is recommended
but not required that this address is read after the initial
device configuration load sequence. A 1 on the
ADDRDATA pin (Auto Addressing Mode) will not cause
this address to automatically increment. The address will
loop back onto itself regardless of the state of
ADDRDATA unless the address on the Data inputs has
been changed with ADDRDATA at 0.
Scan Mode Logic
A scan mode is available in the ACT715 that allows the
user to non-destructively verify the contents of the registers. Scan mode is invoked through reading a scan
address into the address register. The scan address of a
given register is defined by the Data register address + 32.
The internal Clocking signal is disabled when a scan
address is read. Disabling the clock freezes the device in
it's present state. Data can then be serially scanned out
of the data registers through the ODD/EVEN Pin. The
LSB will be scanned out first. Since each register is
12 bits wide, completely scanning out data of the
addressed register will require 12 CLOCK pulses. More
Vectored Clear Address
Addresses 23 (17H) or 55 (37H) is used to clear all registers to zero simultaneously. This function may be desirable to use prior to loading new data into the Data or
Status Registers. This address is read into the device in
a similar fashion as all of the other registers. A 1 on the
©1988 Fairchild Semiconductor Corporation
74ACT715, 74ACT715-R Rev. 1.3
www.fairchildsemi.com
10
74ACT715, 74ACT715-R Programmable Video Sync Generator
ADDRDEC Logic
RS170 Default Register Values
lace. All signals have active low pulses and the clock is
disabled at power up. Registers 13 and 14 are not
involved in the actual signal information. If the Vertical
Interrupt was selected so that a pulse indicating the
active lines would be output.
The tables below show the values programmed for the
RS170 Format (using a 14.31818 MHz clock signal) and
how they compare against the actual EIA RS170 Specifications. The default signals that will be output are
CSYNC, CBLANK, HDRIVE and VDRIVE. The device
initially starts at the beginning of the odd field of inter-
Reg
D Value H
Register Description
REG0
0
000
Status Register (715)
REG0
1024
400
Status Register (715-R)
REG1
23
017
HFP End Time
REG2
91
05B
HSYNC Pulse End Time
REG3
157
09D
HBLANK Pulse End Time
REG4
910
38E
Total Horizontal Clocks
REG5
7
007
VFP End Time
REG6
13
00D
VSYNC Pulse End Time
REG7
41
029
VBLANK Pulse End Time
REG8
525
20D
Total Vertical Lines
REG9
57
039
Equalization Pulse End Time
REG10
410
19A
Serration Pulse Start Time
REG11
1
001
Pulse Interval Start Time
REG12
19
013
Pulse Interval End Time
REG13
41
029
Vertical Interrupt Activate Time
REG14
526
20E
Vertical Interrupt Deactivate Time
REG15
911
38F
Horizontal Drive Start Time
REG16
92
05C
Horizontal Drive End Time
REG17
1
001
Vertical Drive Start Time
REG18
21
015
Vertical Drive End Time
Input Clock
Line Rate
Field Rate
Frame Rate
©1988 Fairchild Semiconductor Corporation
74ACT715, 74ACT715-R Rev. 1.3
Rate
Period
14.31818MHz
15.73426kHz
59.94Hz
29.97Hz
69.841ns
63.556µs
16.683ms
33.367ms
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11
74ACT715, 74ACT715-R Programmable Video Sync Generator
Normal device operation can be resumed by loading in a
non-scan address. As the scanning of the registers is a
non-destructive scan, the device will resume correct
operation from the point at which it was halted.
than 12 CLOCK pulses on the same register will only
cause the MSB to repeat on the output. Re-scanning the
same register will require that register to be reloaded.
The value of the two horizontal counters and 1 vertical
counter can also be scanned out by using address numbers 51–53. Note that before the part will scan out the
data, the LOAD signal must be brought back HIGH.
Signal
Width
µs
%H
Specification (µs)
HFP
22 Clocks
1.536
HSYNC Width
68 Clocks
4.749
7.47
HBLANK Width
156 Clocks
10.895
17.15
10.9 ± 0.2
HDRIVE Width
91 Clocks
6.356
10.00
0.1H ± 0.005H
HEQP Width
34 Clocks
2.375
3.74
2.3 ± 0.1
HSERR Width
68 Clocks
4.749
7.47
4.7 ± 0.1
HPER iod
910 Clocks
63.556
100
Signal
Width
µs
%H
VFP
3 Lines
190.67
6 EQP Pulses
VSYNC Width
3 Lines
190.67
6 Serration Pulses
VBLANK Width
20 Lines
1271.12
VDRIVE Width
11.0 Lines
699.12
VEQP Intrvl
9 Lines
VPERiod (field)
262.5 Lines
16.683 ms
16.683ms/Field
VPERiod (frame)
525 Lines
33.367 ms
33.367ms/Frame
1.5 ± 0.1
4.7 ± 0.1
RS170 Verticle Data
©1988 Fairchild Semiconductor Corporation
74ACT715, 74ACT715-R Rev. 1.3
Specification (µs)
7.62
0.075V ± 0.005V
4.20
0.04V ± 0.006V
3.63
9 Lines/Field
www.fairchildsemi.com
12
74ACT715, 74ACT715-R Programmable Video Sync Generator
RS170 Horizontal Data
For ACT Family Devices over Operating Temperature Range (unless otherwise specified).
TA = +25°C,
CL = 50pF TA = –40°C to +85°C
Symbol
VIH
VIL
VOH
Parameter
VCC (V)
2.0
2.0
1.5
2.0
2.0
VOUT = 0.1V
or VCC – 0.1V
1.5
0.8
0.8
5.5
1.5
0.8
0.8
4.5
IOUT = –50 µA
4.49
4.4
4.4
5.49
5.4
5.4
3.86
3.76
4.86
4.76
0.001
0.1
0.1
0.001
0.1
0.1
0.36
0.44
5.5
Maximum LOW
Level Input Voltage
Maximum LOW
Level Output Voltage
Guaranteed Limits
1.5
4.5
4.5
5.5
4.5
VOL
Typ.
VOUT = 0.1V
or VCC – 0.1V
Minimum HIGH
Level Input Voltage
Minimum HIGH
Level Output Voltage
Conditions
VIN = VIL/VIH,
mA(1)
5.5
IOH = –8
4.5
IOUT = 50µA
5.5
Units
V
V
V
V
V
5.5
VIN = VIL/VIH,
IOH = +8mA(1)
IOLD
Minimum Dynamic
Output Current
5.5
VOLD = 1.65V
32.0
mA
IOHD
Minimum Dynamic
Output Current
5.5
VOHD = 3.85V
–32.0
mA
IIN
Maximum Input
Leakage Current
5.5
VI = VCC , GND
±0.1
±1.0
µA
ICC
Supply Current
Quiescent
5.5
VIN = VCC , GND
8.0
80
µA
ICCT
Maximum ICC/Input
5.5
VIN = VCC – 2.1V
1.5
mA
4.5
0.36
V
0.44
0.6
Notes:
1. All outputs loaded; thresholds on input associated with input under test.
2. Test Load 50pF, 500Ω to Ground.
AC Electrical Characteristics
TA = +25°C,
CL = 50pF
Symbol
Parameter
VCC (V)
Min.
Typ.
TA = –40°C to +85°C,
CL = 50pF
Max.
Min.
Max.
Units
fMAXI
Interlaced fMAX
(HMAX/2 is ODD)
5.0
170
190
150
MHz
fMAX
Non-Interlaced fMAX
(HMAX/2 is EVEN)
5.0
190
220
175
MHz
tPLH1, tPHL1 Clock to Any Output
5.0
4.0
13.0
15.5
3.5
18.5
ns
tPLH2, tPHL2 Clock to ODDEVEN
(Scan Mode)
5.0
4.5
15.0
17.0
3.5
20.5
ns
5.0
4.0
11.5
16.0
3.0
19.5
ns
tPLH3
Load to Outputs
©1988 Fairchild Semiconductor Corporation
74ACT715, 74ACT715-R Rev. 1.3
www.fairchildsemi.com
13
74ACT715, 74ACT715-R Programmable Video Sync Generator
DC Electrical Characteristics
Symbol
Parameter
TA = +25°C
TA = –40°C to +85°C
Typ.
Guaranteed Minimums
VCC (V)
Units
Control Setup Time:
tsc
ADDR/DATA to LOAD–
tsc
L/HBYTE to LOAD–
3.0
4.0
4.5
ns
3.0
4.0
4.5
ns
5.0
2.0
4.0
4.5
ns
5.0
0
1.0
1.0
ns
0
1.0
1.0
ns
5.0
Data Setup Time:
tsd
D7–D0 to LOAD+
Control Hold Time:
thc
LOAD– to ADDR/DATA
thc
LOAD– to L/HBYTE
thd
Data Hold Time:
LOAD+ to D7–D0
5.0
1.0
2.0
2.0
ns
trec
LOAD+ to CLK(3)
5.0
5.5
7.0
8.0
ns
twld–
LOW
5.0
3.0
5.5
5.5
ns
twld+
HIGH
3.0
5.0
7.5
ns
twclr
CLR Pulse Width HIGH
5.0
5.5
6.5
9.5
ns
twck
CLOCK Pulse Width
(HIGH or LOW)
5.0
2.5
3.0
3.5
ns
Load Pulse Width:
Note:
3. Removal of Vectored Reset or Restart to Clock.
Capacitance
Symbol
Conditions
Typ.
Units
CIN
Input Capacitance
Parameter
VCC = 5.0V
7.0
pF
CPD
Power Dissipation Capacitance
VCC = 5.0V
17.0
pF
Figure 6. AC Specifications
©1988 Fairchild Semiconductor Corporation
74ACT715, 74ACT715-R Rev. 1.3
www.fairchildsemi.com
14
74ACT715, 74ACT715-R Programmable Video Sync Generator
AC Operating Requirements
Powering Up
Preprogramming “On-the-Fly”
The ACT715 default value for Bit 10 of the Status Register is 0. This means that when the CLEAR pulse is
applied and the registers are initialized by loading the
default values the CLOCK is disabled. Before operation
can begin, Bit 10 must be changed to a 1 to enable
CLOCK. If the default values are needed (no other programming is required) then Figure 7 illustrates a hardwired solution to facilitate the enabling of the CLOCK
after power-up. Should control signals be difficult to
obtain, Figure 8 illustrates a possible solution to automatically enable the CLOCK upon power-up. Use of the
ACT715-R eliminates the need for most of this circuitry.
Modifications of the Figure 8 circuit can be made to
obtain the lone CLEAR pulse still needed upon power-up.
Although the ACT715 and ACT715-R are completely
programmable, certain limitations must be set as to
when and how the parts can be reprogrammed. Care
must be taken when reprogramming any End Time registers to a new value that is lower than the current value.
Should the reprogramming occur when the counters are
at a count after the new value but before the old value,
then the counters will continue to count up to 4096
before rolling over.
For this reason one of the following two precautions are
recommended when reprogramming “on-the-fly”. The
first recommendation is to reprogram horizontal values
during the horizontal blank interval only and/or vertical
values during the vertical blank interval only. Since this
would require delicate timing requirements the second
recommendation may be more appropriate.
Note that, although during a Vectored Restart none of
the preprogrammed registers are affected, some signals
are affected for the duration of one frame only. These
signals are the Horizontal and Vertical Drive signals.
After a Vectored Restart the beginning of these signals
will occur at the first CLK. The end of the signals will
occur as programmed. At the completion of the first
frame, the signals will resume to their programmed start
and end time.
The second recommendation is to program a Vectored
Restart as the final step of reprogramming. This will
ensure that all registers are set to the newly programmed values and that all counters restart at the first
CLK position. This will avoid overrunning the counter
end times and will maintain the video integrity.
Figure 7. Default RS170 Hardwire Configuration
©1988 Fairchild Semiconductor Corporation
74ACT715, 74ACT715-R Rev. 1.3
www.fairchildsemi.com
15
74ACT715, 74ACT715-R Programmable Video Sync Generator
Additional Applications Information
Figure 8. Circuit for Clear and Load Pulse Generation
©1988 Fairchild Semiconductor Corporation
74ACT715, 74ACT715-R Rev. 1.3
www.fairchildsemi.com
16
74ACT715, 74ACT715-R Programmable Video Sync Generator
Note: A 74HC221A may be substituted for the 74HC423A Pin 6 and Pin 14 must be hardwired to GND
Components
R1: 4.7k
C1: 10µF
R2: 10k
C2: 50pF
74ACT715, 74ACT715-R Programmable Video Sync Generator
Physical Dimensions
Dimensions are in inches (millimeters) unless otherwise noted.
Figure 9. 20-Lead Small Outline Integrated Circuit (SOIC), JEDEC MS-013, 0.300" Wide
Package Number M20B
©1988 Fairchild Semiconductor Corporation
74ACT715, 74ACT715-R Rev. 1.3
www.fairchildsemi.com
17
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FAIRCHILD SEMICONDUCTOR RESERVES THE RIGHT TO MAKE CHANGES WITHOUT FURTHER NOTICE TO ANY PRODUCTS
HEREIN TO IMPROVE RELIABILITY, FUNCTION OR DESIGN. FAIRCHILD DOES NOT ASSUME ANY LIABILITY ARISING OUT OF THE
APPLICATION OR USE OF ANY PRODUCT OR CIRCUIT DESCRIBED HEREIN; NEITHER DOES IT CONVEY ANY LICENSE UNDER
ITS PATENT RIGHTS, NOR THE RIGHTS OF OTHERS. THESE SPECIFICATIONS DO NOT EXPAND THE TERMS OF FAIRCHILD’S
WORLDWIDE TERMS AND CONDITIONS, SPECIFICALLY THE WARRANTY THEREIN, WHICH COVERS THESE PRODUCTS.
LIFE SUPPORT POLICY
FAIRCHILD’S PRODUCTS ARE NOT AUTHORIZED FOR USE AS CRITICAL COMPONENTS IN LIFE SUPPORT DEVICES OR
SYSTEMS WITHOUT THE EXPRESS WRITTEN APPROVAL OF FAIRCHILD SEMICONDUCTOR CORPORATION.
As used herein:
1. Life support devices or systems are devices or systems
which, (a) are intended for surgical implant into the body or
(b) support or sustain life, and (c) whose failure to perform
when properly used in accordance with instructions for use
provided in the labeling, can be reasonably expected to
result in a significant injury of the user.
2. A critical component in any component of a life support,
device, or system whose failure to perform can be
reasonably expected to cause the failure of the life support
device or system, or to affect its safety or effectiveness.
PRODUCT STATUS DEFINITIONS
Definition of Terms
Datasheet Identification
Product Status
Advance Information
Formative or In Design
This datasheet contains the design specifications for product
development. Specifications may change in any manner without notice.
Definition
Preliminary
First Production
This datasheet contains preliminary data; supplementary data will be
published at a later date. Fairchild Semiconductor reserves the right to
make changes at any time without notice to improve design.
No Identification Needed
Full Production
This datasheet contains final specifications. Fairchild Semiconductor
reserves the right to make changes at any time without notice to improve
design.
Obsolete
Not In Production
This datasheet contains specifications on a product that has been
discontinued by Fairchild Semiconductor. The datasheet is printed for
reference information only.
Rev. I24
©1988 Fairchild Semiconductor Corporation
74ACT715, 74ACT715-R Rev. 1.3
www.fairchildsemi.com
18
74ACT715, 74ACT715-R Programmable Video Sync Generator
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exhaustive list of all such trademarks.