Integrated Circuit Systems, Inc. ICS2008B SMPTE Time Code Receiver/Generator General Description Features The ICS2008B, SMPTE Time Code Receiver / Generator chip, is a VLSI device designed in a low power CMOS process. This device provides the timing coordination for Multimedia sight and sound events. Although it is aimed at a PC Multimedia environment, the ICS2008B is easily integrated into products requiring SMPTE time code generation and/or reception in LTC (Longitudinal Time Code) and/or VITC (Vertical Interval Time Code) formats and MTC (MIDI Time Code) translation. • Meets SMPTE VITC Specifications • Meets SMPTE and EBU LTC Specifications • Time Code Burn-in Window – Programmable position, size and character attributes • LTC edge rate control – Conforms to EBU Tr and Tf Specifications • Internal and external sync sources – Genlock to video or house sync inputs – Improved video timing lock during VCR pause and shuttle modes – Internally generated timing from oscillator input – External click input – Internal Timer Allows 1/4 Frame MIDI Time Code Messages • LTC and VITC Generators – Real Time SMPTE Rates: 30Hz, 29.97Hz, 25Hz, 24Hz – Time Code Modes Drop Frame and Color Frame – VITC can be inserted on two lines from 10-40 (SMPTE specifies lines 10-20) – Jam Sync, freewheeling, error bypass/correction, and plus-one-frame capability • LTC Receiver – Synchronize bit rates from 1/30th nominal to 80X nominal playback speed. • VITC Receiver – Reads code from any or all selected scan lines. – VITC search mode, will search through VBI lines until VITC is found. • New UART frequency of 38.4 K for tape transport control Taking its input from composite video, S-Video, or an audio track, the ICS2008B can read SMPTE time code in VITC and LTC formats. Time code output formats are LTC and VITC. All are available simultaneously. A UART is provided for the user to support MTC or tape transport control. The processor interface is compatible with the IBM PC and ISA bus compatible computers and is easily interfaced to other processors and micro-controllers. The ICS2008B is an improved version of the ICS2008, with additional features and capabilities. ICS2008 ICS2008B 2008 2008B Block Diagram ICS2008B Rev G 5/13/10 ICS reserves the right to make changes in the device data identified in this publication without further notice. ICS advises its customers to obtain the latest version of all device data to verify that any information being relied upon by the customer is current and accurate. Package Pinouts 44 43 42 41 40 6 5 4 3 2 LTCOUT LFC XTAL2 XTAL1 AVDD AVSS COUT YOUT C2 Y2 C1 1 7 8 9 10 11 12 13 14 15 16 17 D6 D5 D4 D3 LTCIN+ LTCINCLICK FRAME RESET INTR D7 ICS2008B 39 38 37 36 35 34 33 32 31 30 29 ICS2008B 2 D2 D1 D0 IOW* VDD VSS IOR* UARTCS* SMPTECS* A1 A0 RTS* LRCLK VITCGATE VITCOUT Y1 STHRESH CTHRESH DTHRESH RXD CTS* TXD RTS* LRCLK VITCGATE VITCOUT 44 43 42 41 40 39 38 37 36 35 34 1 33 2 32 3 31 4 30 5 29 6 28 7 27 8 26 9 25 10 24 11 23 12 13 14 15 16 17 18 19 20 21 22 Y1 STHRESH CTHRESH DTHRESH RXD CTS* TXD LTCOUT LFC XTAL2 XTAL1 AVDD AVSS COUT YOUT C2 Y2 C1 D6 D5 D4 D3 LTCIN+ LTCINCLICK FRAME RESET INTR D7 18 19 20 21 22 23 24 25 26 27 28 D2 D1 D0 IOW* VDD VSS IOR* UARTCS* SMPTECS* A1 A0 ICS2008B Pin Descriptions PIN NUMBER TQFP PLCC PIN NAME TYPE 12, 10 18, 16 Y1, Y2 AI 11, 9 17, 15 C1, C2 AI 15 13 14 8 7 41 42 44 43 1 20 22 21 18 16 17 19 4 3 2 24, 23 27 30 25 26 40 38–31 39 5 6 29 28 21 DTHRESH 19 STHRESH 20 CTHRESH 14 Y OUT 13 C OUT 3 FRAME 4 CLICK 6 LTCIN+ 5 LTCIN– 7 LTCOUT 26 LRCLK 28 VITCOUT 27 VITCGATE 24 TxD 22 RxD 23 CTS* 25 RTS* 10 XTAL1 9 XTAL2 8 LFC 30, 29 A1-A0 33 IOR* 36 IOW* 31 SMPTECS* 32 UARTCS* 2 RESET 44–37 D7-D0 1 INTR 11 AVDD 12 AVSS 35 VDD 34 VSS AI AI AI AO AO AI AI AI AI AO O O O O I I O I O AI I I I I I I I/O O P P P P DESC RIPTI ON Video inputs from camera or other source. NOTE: This is also the Y (Luma) input for S-VHS and HI-8 systems. C (Chroma) inputs for S-VHS and HI-8 systems. In NTSC systems, this pin should be tied to its respective Y input. Data Threshold bypass input. SYNC Threshold bypass input. Clamp Threshold bypass input. Video output. This is also the Y (Luma) output in S-Video mode. C (Chroma) output for S-VHS and HI-8 systems. Color Frame A/B input. This input is self biased (See Applications). LTC SYNC input. This input is self biased (See Applications). SMPTE LTC input+. This input is self biased (See Applications). SMPTE LTC input–. This input is self biased (See Applications). SMPTE LTC output SMPTE LTC receive clock output. SMPTE VITC output to video mixer circuit. VITC gate indicates VITC code is being output for video overlay. UART Transmit data UART Receive data Clear to Send Ready to Send 14.318 MHz crystal input. 14.318 MHz crystal oscillator output. Tie to +5 VDC Address bus Read Enable (active low) Write Enable (active low) SMPTE port chip select (active low) UART chip select (active low) Master reset (active high) Bi-directional data bus Interrupt Request (active high) Analog VDD Analog Ground Digital VDD Digital TYPE: A – Analog • P – Power • I – Input • O – Output 2008 2008B ICS2008 3 ICS2008B ICS2008B Functional Description Video Output The video output combines the selected video input with the outputs from the VITC generator and the character generator. It can be a composite or an S-Video output as selected by the SVID bit in the SMPTE control registers. The following is a functional description of the hardware registers in the ICS2008B chip. It also describes how those registers can be utilized by the software to facilitate specific application services. VITC code is generated from data in the VITC generator buffer and output during the selected line time(s). The CRC and synchronizing bits are automatically generated by the VITC generator, but all of the data fields are sent directly from the buffer with no modification. Hardware Environments The ICS2008B operates as a peripheral to a processor such as a PC or a single chip microprocessor. Many of the real time requirements are satisfied by double buffering both incoming and outgoing time codes. A character generator is provided to insert the time code in a burn-in window which overlays the incoming video. The vertical and horizontal position of the burn-in window is programmable. LTC Input LTCIN is a differential analog input feeding a comparator with hysteresis. It requires capacitive coupling to the LTC source. The output of the comparator goes to the LTC receiver, which is capable of receiving LTC in a forward or backward direction at a rate from 1/30 th to 80X nominal frame rates. The incoming LTC data is sampled with a phaselocked clock and loaded into the receive buffer following the receipt of a valid LTC SYNC pattern. When a complete frame has been received, an interrupt is generated. SMPTE SYNC Sources A time code generator must have a SYNC input from a stable source in order to position the LTC code properly on a audio track of video tape or film. Three SYNC sources, video, click input, and free running, are available. In the case of a video tape, LTC code must start within plus or minus one line of the beginning of line 5. This requires “Genlocking” to the incoming video. The video timing section locks to the video’s horizontal and vertical SYNC signal and generates a SMPTE SYNC. If some external SYNC source is available it can be input on the CLICK input. Otherwise, a free running SMPTE SYNC is generated from the oscillator at the selected frame rate. LTC Output The LTC output can be analog or digital. When set up as an analog output, it can drive a high impedance load. The LTC generator outputs a LTC frame at the selected frame rate, such as 24 Hz, 25 Hz, 29.97 Hz or 30 Hz, and starts the frame based on a start time generated by the selected LTC SYNC source. Video Timing Generator The video timing generator is “Genlocked” to the video input’s SYNC separator. It extracts NTSC or PAL timing information from the video input and generates line and pixel rate timing for the VITC receiver, VITC generator, LTC generator and character generator. If no video input is present, it generates free running timing. The output edge rate is programmable for SMPTE code (25 µsec) and EBU code (50 µsec) rise and fall times. Video Inputs There are two sets of video inputs. In a composite NTSC or PAL system, the Y input is the only one used. It is capacitively coupled to the source. In S-Video systems, capacitively couple Y and C to their respective sources. Proper termination of the source should be observed. Unused inputs may be left open. One of the two video sources is selected by the VIDSEL bit in the SMPTE control registers as the video SYNC source. Internal timers are synchronized with the incoming video to extract timing information used to receive and generate VITC. Overlay Character Generator It is sometimes desirable to display the time code on a video display along with the picture. A character generator is provided for that purpose. The time code display, or burn-in window, can be positioned anywhere on the screen. It can be displayed in two sizes with white or black characters on a black, white or live video background. The VITC receiver samples the incoming video looking for a valid VITC code on selected scan lines. When a valid code is received it is written to a VITC receive buffer. More than one line can contain VITC code, and the codes can be different. For this reason, VITC codes from selected lines of a frame are written to separate VITC buffers. ICS2008B 4 ICS2008B UART LRI, LXI, VLI and TMI reflect the status of the potential interrupt sources to the processor. When a bit is set to one and the corresponding enable bit, LRIEN, LXIEN or VLIEN, is also set, the INTR output will be activated. Interrupts are cleared by reading SMPTE0. A general purpose UART is provided for MIDI, video transport control, etc. Most serial interface transport controls use 9600 and 38.4K BAUD. The CTS and RTS modem controls are needed in these applications. MIDI ports use 31.25K BAUD, but they do not require modem controls. The receiver includes a four byte FIFO to reduce the real time interrupt servicing requirements. This is particularly important in MIDI applications because of the high data rate and the fact that many MIDI messages are three bytes long. The transmitter is doubled buffered. Interrupts can be generated on both receiver data available and/or transmit buffer empty. 7 The ICS2008B supports standard microprocessor interfaces and busses, such as the PC bus, to allow access to six control/ status and data registers. These six registers are organized into two groups, one set of four for SMPTE control and the other set of two for direct UART port control. Each set of registers is selected with its own chip select, SMPTECS* and UARTCS.* SMPTE Registers 0 0 S M P TE 0 -InterruptC ontrol/S tatus 0 0 1 S M P TE 1 -S M P TE S tatus 0 1 0 S M P TE 2 -IndirectA ddress R egister 0 1 1 S M P TE 3 -IndirectR egisterD ata 2 1 0 SMPTE0 LXI — This bit indicates that a LTC transmit interrupt has occurred. When this bit is set, and the corresponding LXIEN bit has been set, the INTR output will be activated. The LTC transmit interrupt is activated after the transfer of LTC transmit data to the output buffer. This occurs after LTXEN is set to one and after the 72nd LTC transmits bit time of the current frame, “N.” Data loaded after this interrupt will appear in output frame “N+2” since the transmitter is double buffered. The SMPTE register set allows access to four direct and 64 indirect registers. The first two direct access registers addressed at locations 0 and 1 are for status and interrupt control. The 64 indirect registers are accessed by writing an indirect address into SMPTE2 and reading from or writing to SMPTE3. If the AUTOINC bit in SMPTE2 is set to 1, the indirect register address is automatically incremented after an access to SMPTE3. This eases the task of reading or writing sequential indirect locations. 0 3 LRI — This bit indicates that a LTC receive interrupt has occurred. In order for an actual processor interrupt to occur, the LRIEN bit must also be set. An LRI interrupt occurs upon reception of the last byte of LTC receive data which was preceded by a valid LTC SYNC pattern. That is after the 64th LTC receive bit time in the forward direction. At normal frame rates, if the LTC transmitter is synchronized with the LTC receiver, there is about 3 milliseconds after this interrupt before the LTC transmit data for the next output frame is transferred to the output buffer. Processor Interface AA00 4 LRI (LTC RCV Interrupt) LXI (LTC XMT Interrupt) VLI (Video Line Interrupt) LRIEN (1-enable, 0-disable) LXIEN (1-enable, 0-disable) VLIEN (1-enable, 0-disable) TMI (Timer Interrupt) TMIEN (1-enable, 0-disable) The interrupt timer is a general purpose 10 bit timer with three clock sources (100 kHz, the LTC receive clock and the LTC transmit clock). Although the timer is general purpose in nature, its main purpose is to facilitate the timed generation of MIDI time code messages. AA11 5 Interrupt Control/Status Interrupt Timer S M P TE C S * 6 VLI — This is a status bit that indicates that the video line selected via the Video Interrupt Line Register, VR9, has passed. When the VLIEN bit is also set, the processor will be interrupted. This interrupt can be used by the processor to determine when to sample the VITC time code when time locked to a video source. It will also be used to facilitate detection of LTC time code dropout and off speed LTC code, e.g. shuttling operations. R E G IS T E R TMI — This bit indicates that a timer interrupt has occurred. When the TMIEN bit is also set to a one, the INTR output will be activated. This interrupt is intended to facilitate timing MIDI clocks and MIDI Quarter Frame messages. The SMPTE0 Register contains the SMPTE interrupt controls and status and the VITC read status. The four interrupt bits, 5 ICS2008B ICS2008B The SMPTE Status Register is a read only register which contains video and LTC status. 7 6 5 4 3 2 1 0 the field and frame from the selected video input. The even/ odd fields are identified by a 1/0 in bit 6. Bit 7, FRAME, is valid for PAL video after line 6. Bit 6, FIELD, is valid after line 5 in NTSC mode or line 2 in PAL mode. SMPTE1 SMPTE Status Register The SMPTE2 register is the register which points to the 57 indirect registers. When reading or writing an indirect register, the value in the ADDRESS pointer, SMPTE2 bits 5 to 0, is the address of the register accessed through SMPTE3. If the AUTOINC bit is set to one, at the end of an access cycle to SMPTE3, ADDRESS will automatically increment. Otherwise, ADDRESS holds its value. FRAMEIN (input = 1-high, 0-low) CLICK (input = 1-high, 0-low) LTCLOCK (1-locked, 0-not locked) CODEDIR (1-bkwd, 0-fwd) Reserved VLOCK (1-locked, 0-not locked) FIELD FRAME (PAL only) 7 FRAMEIN — This bit indicates the state of the FRAME input pin. It is used as an alternate source for B/A frame status. This is useful when the quality of the video signal is not good enough to extract the B/A frame status. 7 1 0 Receiving LTC (FORWARD) 1 1 Receiving LTC (BACKWARD) 1 0 SMPTE2 6 5 4 3 2 1 0 SMPTE3 Indirect Registers The following describes the functions controlled by the indirect registers. A map of the indirect registers follows this section, on page 11. LTC Read Registers IR0-IR7 (read-only) These read only registers contain the LTC data as received. Both forward and backward frames are stored with LTC bit 0 in the LSB of IR0 and LTC bit 63 in the MSB of IR7. VLOCK — This is a hardware driven bit which indicates that genlock has been achieved with the selected video SYNC source. LTC Write Registers IR8-IRF These registers contain the data to be sent by the LTC transmitter. The LSB of IR8 is sent as LTC bit 0, and the MSB of IRF is sent as LTC bit 63. The data is transmitted as it is stored in IR8-IRF. FRAME & FIELD — The hardware SYNC separator detects ICS2008B 2 Indirect Address Register LTC RECEIVER STATUS Looking for SYNC pattern 3 SMPTE3 is the data register through which all of the indirect registers are accessed. The address for a given register must first be set in SMPTE2 before accessing that register. CODEDIR — The code direction bit works in conjunction with the LTCLOCK bit. When the LTCLOCK bit is set to one, the CODEDIR bit is valid. Otherwise, it is not. See the table below. X 4 ADDRESS Reserved AUTOINC (1-increment, 0-hold) LTCLOCK — When a valid forward or backward LTC sync pattern is detected, this bit is set to one. It is reset to zero when an expected LTC sync pattern is missed or an invalid LTC bit is detected. 0 5 Indirect Address Register CLICK — This bit indicates the state of the CLICK input pin. It can be used as a synchronization source for the LTC transmitter. LTCLOCK CODEDIR 6 6 ICS2008B VITC Read 1 Registers IR10-IR17 (read-only) BI Character Registers IR2A-IR2D These read only registers contain the VITC data as received from the video line selected in IR30. The frame is stored with VITC bit 2 in the LSB of IR10 and VITC bit 80 in the MSB of IR17. Note that a binary 10 sync pattern precedes every eight data bits of the VITC frame. The 10 sync pattern is not stored. The CRC is checked by the VITC receiver, and the result is reported in IR30. These registers contain the character codes used for the SMPTE time code in the burn-in window which overlays the source in the video output. An internal character generator converts the BCD nibbles to display characters. 7 VITC Read 2 Registers IR18-IR1F (read-only) These registers contain the data to be output by the VITC generator. The VITC frame is output with the LSB of IR20 in VITC bit 2 and the MSB of IR27 in VITC bit 80. Note that the binary 10 sync pattern which precedes every eight data bits of the VITC frame is automatically generated by the VITC generator. The CRC is also automatically generated by the VITC generator. 3 2 1 0 2 1 0 Burn-in Window Registers IR2A IR2B IR2C IR2D Ones – (Frame) – (Seconds) – (Minutes) – (Hours) CHARACTER CODE CHARACTER 0 1 2 3 4 5 6 7 0 1 2 3 4 5 6 7 8 9 A B C D E F 8 9 Do Not Use ? _ Blank VITC code is normally output on two separate video lines in each field for redundancy. These two registers allow the individual line selection & output enables for the two VITC lines. The next two registers control the position of the SMPTE video display, burn-in, window within the video raster. IR28 selects the video column (horizontal position) in which the burn-in window starts. 4 3 ITC Write Line Select Registers IR2E & IR2F BI Window Registers IR28 & 29 5 4 CODE VITC Write Registers IR20-IR27 6 5 Tens As with the VITC Read 1 registers, these read only registers contain the VITC data as received from the video line selected in IR31. The frame is stored with VITC bit 2 in the LSB of IR18 and VITC bit 80 in the MSB of IR1F. The result of the CRC check is reported in IR31. 7 6 7 6 5 4 3 2 1 0 IR2E IR28 VITC Write Line 1 Burn-in Window Column Write Line #10-40 (N+10) Reserved VITC Write Enable (1-enable) Column 7 IR29 selects the video line which starts the SMPTE video display window in the video output. When this register is set to zero, there will be no Burn-In Window displayed in the video output. 7 6 5 4 3 2 1 0 6 5 4 3 2 1 0 IR2F VITC Write Line 2 Write Line #10-40 (N+10) Reserved VITC Write Enable (1-enable) IR29 Write Line – Selects the video line on which the VITC code will be output. The video line on which the code is output will be the number in this register plus 10; e.g. writing a one to this register will cause the code to be output on line 11. Burn-in Window Line Line (00 - disable) VITC Write Enable – Enables the output of VITC code on the specified line. 7 ICS2008B ICS2008B VITC Read Line Select Registers IR30-IR31 7 6 5 4 3 2 1 0 Video Control Register IR32 7 IR30 VITC Read Line 1 6 5 4 3 2 1 0 5 4 3 2 1 0 IR32 Video Control Register GENLOCK ENABLE (1-lock, 0-freewheel) VTRES - Video Timing Reset (1-reset) VSYNCEL - Video SYNC Source Select VITCSEL - VITC Source Select VOUTSEL - Video Output Select VID1_S - Video1 S-Video Select VID2_S - Video2 S-Video Select PAL/NTSC (1-PAL, 0-NTSC) Read Line 10-40 (N+10) CRCERR (1-error, 0-OK) (r/o) NOCODE (1-no code, 0-code) (r/o) VITC Read Enable (1-enable) 7 6 IR31 VITC Read Line 2 GENLOCK ENABLE — When set to one, this bit enables the genlock circuits to sync to the selected video input signal. When reset to 0, the video sync will “freewheel,” generating video timing from the internal oscillator. The freewheel mode would be selected when striping LTC to allow synchronization with a MIDI sequencer or other strictly timed audio source. Read Line 10-40 (N+10) CRCERR (1-error, 0-OK) (r/o) NOCODE (1-no code, 0-code) (r/o) VITC Read Enable (1-enable) As with the VITC Write Line Register, these registers allow control of the individual redundant VITC read lines. The processor can also reprogram these dynamically to allow for scanning of VITC code when the source lines are unknown. VTRES — When set to one, this bit clears the video timing counters to dot zero of line 1 of field 1. This is useful when the video is free running, not genlocked and LTC sync needs to be synchronized to an event such as the CLICK input. Read Line – Selects the line from which VITC code is to be read within each field. It works identically to the Write Line in that the video line selected is the number in this register plus 10. VSYNCSEL — When set to one, this bit selects the video input source from Video2 (Y2) to be the SYNC source for the internal video timing. Otherwise, when reset to zero, Video1 (Y1) is selected. Auto line scanning is enabled by writing a 1Fh to the Read Line field. This causes the VITC reader to search for time code. If VITC Read Line 1 is set to search, it starts with line 10 and quits when it finds a valid time code or when it reaches line 41. Searching with VITC Read Line 2 starts after VITC Read Line 1. In the case of searching for both VITC Read Lines 1 and 2, VITC Read Line 2 starts searching after the first valid time code has been found. However, if VITC Read Line 1 is set to a specific line, VITC Read Line 2 starts after that specified line regardless of whether valid time code was received. In any case, the search terminates after line 41. VITCSEL — When set to one, this bit selects the video input source from Video2 (Y2) to be the VITC time code source for the VITC receiver. Otherwise, when reset to zero, Video1 (Y1) is selected. VOUTSEL — When set to one, this bit selects the video input source from Video2 (Y2, C2) to be output on the video outputs (YOUT, COUT). When reset to zero, Video1 (Y1, C1) are selected. CRCERR — This bit is reset to zero when a valid VITC code has been received. It is valid from the end of the selected video line until the end of the selected line in the next field. VID1_S — When set to one, this bit causes the Video1 source to be treated as S-Video. Otherwise, when cleared to zero, the Video1 source is treated as composite video. NOCODE — This bit is set when a framing error occurs in the VITC code, i.e. not all the bits of the code were received by the time the end of the video line occurred. Both CRCERR and NOCODE must be zero to qualify a VITC code. ICS2008B VID2_S — When set to one, this bit causes the Video2 source to be treated as S-Video. Otherwise, when cleared to zero, the Video2 source is treated as composite video. 8 ICS2008B PAL/NTSC — When set to one, this bit causes the video to be synchronized with PAL timing. Otherwise, when cleared to zero, video is synchronized with NTSC timing. complete LTC frames are transmitted. The data to be sent by the LTC transmitter should be loaded into the associated RAM buffer before the LTCEN bit is set. Video Interrupt Line Register IR33 LTC SYNC — These bits select the LTC transmit sync source. Values 00, 01, 10 and 11 select start of video line 5, rising edge of CLICK, LTC receive sync pattern detect and write to IR3F respectively as the sync event. Care should be taken to disable LTXEN before changing the LTC SYNC select. Otherwise, an erroneous sync may be generated. This register selects the video line after which the Video Line Interrupt will occur. The actual video line number is the number in the register plus one. 7 6 5 4 3 2 1 0 IR33 Video Interrupt Line Register LTCOUTSEL — This bit, when set to 1, causes the LTCOUT pin to be a digital output. When cleared to 0, the LTCOUT pin is an analog output with gain control. Video Interrupt Line (1 to 64) Reserved 7 6 5 4 3 2 1 0 LTC Control Registers IR34 – IR37 7 6 5 4 3 2 1 0 IR35 LTC Control Register 2 IR34 LTCGAIN LTC Output Gain 0: off 4: -24dB 1: 5: -21dB 2: 6: -18dB 3: 7: -15dB Reserved LTC Control Register 1 EDGERATE (1-25µsec., 1-50µsec.) LXTFREE (0-LTCYNC start) (1-free start) Reserved (Set to zero) LXCLKSEL (0-internal clock) (1-LTC receive clock) LTXEN LTC Transmit Enable LTC SYNC (00-video, 01-CLICK) 8: -12dB 9: -9 dB A: -6 dB B: -3 dB C: 0dB D: 3dB E: 6dB F: 9dB LTCGAIN — This bit sets the signal gain on the LTC audio output. The output gain is selectable in 3dB increments from – 24dB to + 9dB referenced to 0VU = –10 dbV. When this register is set to zero, there is no LTC audio output. (10-LTC RCV, 11-Software) LTCOUTSEL (1-digital, 0-analog) These next two write only registers, IR36 and IR37, control the LTC transmit bit rate. The transmit clock generator is a 12bit divider. The upper four bits of IR37 are not used. Each bit requires two clocks. Therefore, the LTC transmit bit rate is the input clock divided by the divider value +1, then divided by two. Since there are 80 bit times for each LTC frame, the LTC frame rate is the bit rate divided by 80. • LTC Tx Clock = 14.318 MHz /(Divider Value +1) • LTC Bit Rate = LTC Tx Clock/2 • LTC Frame Rate = LTC Bit Rate/80 The table below shows the divider values for some of the most commonly used LTC frame rates. EDGERATE — This bit selects the LTC output edge rate. SMPTE specifies 25 µ sec rise and fall times while EBU specifies 50 µsec. LTXFREE — This bit controls the LTC frame start of the LTC transmitter. When reset to zero, the start of a LTC output frame is triggered by the selected LTC SYNC source. Otherwise, when set to one, the end of a LTC frame will trigger the start of the next. The first LTC transmit frame must be triggered by one of the SYNC sources. LXCLKSEL — This bit controls the source for the LTC transmit clock divider input. A 0 selects the internal 14.318 MHz clock and a 1 selects the LTC receive clock. When the LTC receive clock is selected as the source to the LTC transmit clock divider, the clock rate is first doubled before being input to the divider so that loading a divider value of 001 will result in the LTC transmit clock running at the exact same rate as the LTCreceive clock. LTC FRAME RATE 30 Hz 29.97 Hz 25 Hz 24 Hz LTXEN — This bit, when set to 1, enables output of LTC code on the LTCOUT output pin. LTXEN is synchronized with the selected LTC SYNC source to ensure that only 7 6 5 4 3 2 1 0 DIVIDER VALUE BA6h BA9h DFBh E90h LTC Bit Time (write only) IR36 – (low byte) IR37 – (high byte) 9 ICS2008B ICS2008B 7 Timer Control Registers IR3C & IR3D 6 5 4 3 2 1 0 These two registers control the interrupt timer. It should be noted that IR3C is a write only register, while IR3D is a read/ write register. 7 6 5 4 3 2 1 0 Burn-in Window Attributes BLINK [1-blink, 0 -stable] WINATTR (00 -white on black) (01-black on white) (10-white on background) (11-black on background) (10-reserved, 11-100 kHz) WINSIZE (1-large, 0-normal) HSF (1-enable, 0-disable) Reserved IR3C Timer Value (w/o) TMRVAL [7:0] 7 6 5 4 3 2 1 0 IR3E IR3D Timer Control (r/w) BLINK — This bit controls the upper dot of the right-most colon in the burn-in-window. When set to zero, the upper dot is on. When set to one, it is off. This feature can be used to indicate odd and even fields in the time code display window. TMRVAL [9:8] Reserved CLKSEL (00-LXCLK, 01-LRCLK) (10-reserved, 11-100 kHz) RUN (1-run, 0-stop) WINATTR — These two bits control the color of the characters and the background in the burn-in window. When the most significant bit of this field is a one, the background is the incoming video. TMRVAL — These ten bits set the divider value for the interrupt timer. The interrupt rate is the input clock rate divided by the value plus one. WINSIZ — This bit controls the size of the burn-in window. The difference in size between a large and a normal-sized window is 32 scan lines high, while a large window is 64 scan lines high. Interrupt Rate = CLOCK /(TMRVAL+1) CLKSEL — This 2 bit field selects the clock source for the interrupt timer. The 100 kHz input is actually 100.126 kHz. It is the crystal frequency divided by 143. HSF (Head Switch Filter) — When set to one, this bit causes the clamp circuit to ignore head switch transients and horizontal sync during the last six to seven lines before the vertical front porch. Otherwise, the clamp circuit responds always. RUN — This bit starts and stops the timer. When set to one, the timer is running. When set to zero, the timer is stopped. LTC Soft Sync IR3F IR3f is not a register at all. It is simply an address which, when written and the LTC SYNC select is set for Soft SYNC, generates LTC SYNC for the LTC transmitter. 7 6 5 4 3 2 1 0 IR3F LTC Soft SYNC (w/o, no data) ICS2008B 10 ICS2008B Indirect Register Map 7 LTC Read 00 01 02 03 04 05 06 07 LTC 08 Write ... OF VITC 10 READ1 11 12 13 14 15 16 17 VITC 18 Read2 . . . 1F VITC 20 Write ... 27 Regs 28 29 2A 2B 2C 2D 2E 2F 30 31 32 33 34 35 36 37 38 39 3A 3B 3C 3D 3E 3F 6 5 BINARY GROUP 1 BINARY GROUP 2 BINARY GROUP 3 BINARY GROUP 4 BINARY GROUP 5 BINARY GROUP 6 BINARY GROUP 7 BINARY GROUP 8 4 3 COLR FRAME PHASE CORR BG FLAG 55 BG FLAG 75 2 1 0 FRAME UNITS DROP FRAME FRAMES TENS SECONDS UNITS SECONDS TENS MINUTES UNITS MINUTES TENS HOURS UNITS UNASSIGNED HOURS TENS SAME BIT DEFINITION AS LTC READ BUFFER BINARY GROUP 1 BINARY GROUP 2 BINARY GROUP 3 BINARY GROUP 4 BINARY GROUP 5 BINARY GROUP 6 BINARY GROUP 7 BINARY GROUP 8 FRAME UNITS COLR FRAME DROP FRAME FRAMES TENS SECONDS UNITS FIELD MARK SECONDS TENS MINUTES UNITS BG FLAG 55 MINUTES TENS HOURS UNITS BG FLAG 75 UNASSIGNED HOURS TENS SAME BIT DEFINITION AS VITC READ1 BUFFER SAME BIT DEFINITION AS VITC READ1 BUFFER - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - BURN-IN WINDOW COLUMN - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - ---------------------------------BURN-IN WINDOW LINE ------------------------------------------------------------------FRAMES ------------------------------------------------------------------SECONDS ------------------------------------------------------------------MINUTES ------------------------------------------------------------------HOURS ---------------------------------VITC1WE 0 0 ----------VITC WRITE LINE 1 ----------VITC2WE 0 0 ----------VITC WRITE LINE 2 ----------VITC1RE NOCODE1 CRCERR1 - - - - - - - - - - VITC READ LINE 1 ----------VITC2RE NOCODE2 CRCERR2 - - - - - - - - - - VITC READ LINE 2 ----------PAL VID2_S VID1_S VOUTSEL VITCSEL VSYNCSEL VTRES GEN_EN 0 0 - - - - - - - - - - - - - - - - - - - - - - VIDEO LINE INTERRUPT (LINE#) - - - - - - - - - - - - - - - - LTCOUTSEL - - - - LTCSYNCSEL - - - LTXEN LXCLKSEL 0 LTXFREE EDGE RATE 0 0 0 - - - - - - - - - - - - - - - - - - LTC GAIN - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - FRAME RATE (low byte, write only) - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 0 0 0 0 - - - - - - - FRAME RATE (high byte, write only) - - - - - - reserved reserved reserved reserved - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - TIMER VALUE (low byte, write only) - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - RUN CLKSEL 0 0 0 TIMER VALUE (high) 0 0 0 HSF WIN_SIZE WINDOW ATTRIBUTE BLINK - - - - - - - - - - - - - - - SOFT LTC SYNC (write only, no data) - - - - - - - - - - - - - - - - 11 ICS2008B ICS2008B 7 UART Registers 6 5 4 3 2 1 0 The UART emulates a 6850. Since the UART is tailored to MIDI applications, some of the generic 6850 functions have been omitted. The registers described below reflect that. UART2 Status Register RBF – Receive Buffer Full (1-Full) TBE – Transmit Buffer Empty (1-Empty) Reserved CTS – Clear-to-Send (0-Active) FE – Framing Error (1-Error) OV – Receiver Overrun (1-Overrun) Reserved IRQ – Interrupt Request (1-Active) The two UART registers, Command/Status and Data, are accessible to the processor as shown in the following map. UARTCS* A1 A0 REGISTER 0 X 0 UART Command/Status Register 0 X 1 UART Data Register UART0 (read) RBF — Bit 0, Receive Buffer Full, is set to 1 when read data is available in the UART data register. It is cleared to 0 when the UART data register is read. UART Command/Status Register 7 6 5 4 3 2 1 0 TBE — Bit 1, Transmit Buffer Empty, is cleared to 0 when data is written to the UART data register. It is set to 1 when the UART transfers that data to its output shift register. UART0 (write) UART Command Register Bit Rate (00 - 9600, 10 - 38.4K) (01 - 31.25K, 11 - Reset) Reserved TC1, TC0 Transmit Control 00 - RTS* – low, Tx IRQ disabled 01 - RTS* – low, Tx IRQ enabled 10 - RTS* – high, Tx IRQ disabled 11 - RTS* – low, Transmit BREAK, Tx IRQ disabled RIE - Receive Interrupt Enable CTS — Bit 3, Clear-to-Send, is an active low status bit indicating the state of the CTS* input pin. A 0 in this bit position indicates that the modem or receiving device is ready to receive characters. A 1 indicates not ready. When CTS is inactive, 1, TBE is held at 0, the not-empty state. FE — Bit 4, Framing Error, when set to 1, indicates that the receive character was improperly framed by the start and stop bits. It is detected by the absence of the first stop bit. This indicator is valid as long as the character data is valid. OV — Bit 5, Receiver Overrun, is an error flag indicating that one or more characters in the data stream has been lost. It is set to 1 when a new character overwrites an old character which has not been read. The overrun error is cleared to 0 when a character is read from the UART data register. Bit Rate — This field selects the bit rate for data transmit and receive. After a master reset, its value is 11. One of the three bit rates must be selected in order to start the UART’s operation. Writing a 11 will reset the UART. IRQ — Bit 7, Interrupt Request, is a status bit which reflects the state of the interrupt request from the UART to the processor. When IRQ is 1, an interrupt is pending. Otherwise, no interrupt is pending. TC1, TC0 — Bits 6 and 5, Transmit Control, provide control for transmit interrupt (when TBE is true), RTS control, and transmit BREAK level. RIE — Bit 7, Receive interrupt enable, when set to one, enables the UART to interrupt the processor when the receive buffer is full or a receive overrun has occurred. The UART data register is actually two registers, a transmit buffer and a receive buffer. Writing to the data register causes the transmit buffer to be written. Reading from the data register causes the receive buffer to be read. 7 6 5 4 3 2 1 0 UART1 UART Data Register ICS2008B 12 ICS2008B Absolute Maximum Ratings Operating Temperature . . . . . . . . . . . . . . . . . . 0°C to +70°C Storage Temperature . . . . . . . . . . . . . . . . . . . . – 65°C to +150°C Voltage on any pin to GND . . . . . . . . . . . . . . – 0.5V to VDD + 0.5V Voltage on VDD to GND . . . . . . . . . . . . . . . . . – 0.5V to +7.0V Power Dissipation . . . . . . . . . . . . . . . . . . . . . . 1.0 watt Stresses above those listed under Absolute Maximum Ratings above may cause permanent damage to the device. This is a stress rating only. Operating the device at these levels is not recommended, and specifications are not implied. DC Electrical Characteristic TA = 0°C to +70°C; VDD = 5V ± 10%; GND = 0V PARAMETER Digital Inputs Input Low Voltage Input High Voltage Input Leakage Current Input Capacitance Digital Outputs Output Low Voltage (IOL = 4.0mA) Output High Voltage (IOH = 0.4mA) Tri-State Current Output Capacitance Bi-Directional Capacitance Analog Inputs Video Input Voltage (Y1, Y2, C1, C2) LTC Differential Input Voltage LTCIN+, LTCIN–, CLICK, FRAME input voltage CLICK and FRAME bias voltage Analog Outputs Video Output Voltage (YOUT, COUT) LTC Output Voltage (Volume set at max.; Iout=35mA) LTC Output Voltage Amplitude Control Step LTC Output Voltage Amplitude Range Analog VDD Supply Current Digital VDD Supply Current SYMBOL MIN VIL VIH IIL CIN –0.5 2.0 VOL VOH IOZ TYP MAX UNITS 0.8 VDD+0.5 10 7 V V A pF 0.4 V V A pF pF 2.4 10 10 10 1.0 0.1 –0.3 VDD+0.3 VDD/3 1.0 2.0 3 33 IDD1 IDD2 13 50 5 ICS2008B Vp-p Vp-p V V Vp-p Vp-p dB dB mA mA ICS2008B AC Electrical Characteristics TA = 0°C to +70°C; VDD = 5V ± 10%; GND = 0V PARAMETER SYMBOL MIN Address setup to IOR* or IOW* command Address hold from IOR* or IOW* command Read pulse width Access time Output enable access time Data hold from IOR* high Read command inactive time Write pulse width Write data setup to IOW* high Write data hold from IOW* high Write command inactive time CS* inactive time (Note 1) UART Port Bit Rate (Command Register [1:0] = 00) UART Port Bit Rate (Command Register [1:0] = 01) UART Port Bit Rate (Command Register [1:0] = 10) tACS tAH tRD tACC tOE tRDH tRHRL tWR tWDS tWDH tWHWL tCHCL 20 10 150 TYP MAX 150 50 10 70 150 20 10 70 20 9.6 31.25 38.4 Notes: 1. This timing parameter must be met for proper operation of indirect register access using auto-increment. FIGURE 3 — Host Processor Bus Timing ICS2008B 14 UNITS ns ns ns ns ns ns ns ns ns ns ns ns kHz kHz kHz ICS2008B Video Outputs Applications YOUT and COUT are outputs of analog multiplexers which select the video source from Y1, C1 or Y2, C2. These outputs are not buffered, so minimizes signal distortion. It is, therefore, important to keep the capacitive and resistive load on the YOUT and Fig. 7 - Video Output COUT pins to a minimum. If DC coupling is desired, the plus input of the opamp should be high impedance with a low bias current, and its output should be able to drive a 75 ohm load with an appropriate video bandwidth. In general, composite NTSC and S-video signals have a bandwidth of 4.2 MHz. A minimum output buffer bandwidth of 10 MHz is recommended. Care should be taken in board layout to minimize stray capacitance on the YOUT and COUT pins. Otherwise, there could be high frequency roll-off which could result in a loss of chrominance amplitude. Crystal Oscillator This oscillator will operate properly with either a serial or parallel resonant crystal. If frequency accuracy is critical, a parallel resonant crystal is recommended. Fig. 4 - Crystal Oscillator Threshold Bypass Pins These pins provide access to the internal references for clamp level (CTHRESH), SYNC slicer (STHRESH), and data slicer (DTHRESH). In general, these pins are left open, and the levels are output. However, should the user want to set other levels, these pins can be over-driven with the desired threshold level(s). CTHRESH is the threshold to which the input video sync tips are clamped. The CTHRESH level is nominally 1.3V. With the incoming video riding on this 1.3V DC level, the internal SYNC separator sizes the video at 20 IRE up from the SYNC tips. This level, STHRESH, is nomiFig. 5 – Threshold Bias nally 0.14V above CTHRESH. The SYNC separator ignores short pulses which fall below the STHRESH level such as these that come from the chroma component of the video. DTHRESH is the data slicer reference. It is nominally 0.57V above CTHRESH. Self Biased Inputs The CLICK and FRAME inputs are biased to 1/3 VDD and connected to plus inputs of two comparators. The minus inputs are internally biased to 1/3 VDD. When CLICK or FRAME sources are analog, they should be capacitively coupled to the input pin. However, if the sources are digital, they may be tied to the pins directly. It is important to make sure that the digital levels into these pins swing above and below the 1/3 VDD threshold of the comparators. This is not a problem with digital CMOS sources, but it could be with TTL sources. Video Inputs Y1, Y2, C1 and C2 pins must be capacitively coupled to the terminated video source(s). These inputs are clamped to the CTHRESH level. A typical coupling capacitance is 0.1µF. LTCIN + and LTCIN – are comparator inputs for the Fig. 8 - Self Biased Inputs LTC input. This differential input is provided to maximize noise immunity. If the LTC source is single ended, the LTCIN – should be capacitively coupled to the ground reference of that source. If the LTC source is digital, set the LTCIN – to the desired threshold, and connect the digital source to LTCIN+. Fig. 6 – S-Video Input 15 ICS2008B ICS2008B Programming LRI bit is set to one in the SMPTE0 register. If the LRIEN bit (SMPTE0) is set to a one, an interrupt will be generated. The interrupt is cleared when the SMPTE0 register is read. The data in the LTC receive buffer remains valid until the next LTC frame has been completely received. The ICS2008B is a SMPTE time code input/output device with a UART which can be used as a MIDI UART or transport control UART. All of the time critical functions to read and generate time code are performed by the chip’s hardware, but all of the intelligence for processing time codes and generating the time code values are performed via an external processor. This makes the ICS2008B flexible enough for a broad range of applications without making the processing requirements on the host system too great. LTC input data is available in the LTC Read registers after the last LTC data bit has been received. It is not necessary to wait for the LTC SYNC pattern to be complete. When LTC read data is available the LRI bit in SMPTE0 is set to one. If LRIEN is also set to one, an interrupt is generated. LRI and the interrupt are cleared by reading SMPTE0. Data will remain valid until the last LTC data bit of the next frame has been received. Indirect Register Access Indirect registers are accessed via the SMPTE2 (address) and SMPTE3 (data) registers. To read an indirect register, the program must first write its address to SMPTE2. Then the data is read from SMPTE3. Writing to an indirect register is similar. First, the address is written to SMPTE2. Then the data is written to SMPTE3. The SMPTE1 register contains two status bits which indicate whether LTC data is being received and if so which direction. LTCLOCK is set to one when the LTC receiver has received a valid LTC SYNC pattern and data is still coming in. CODEDIR indicates the direction of the LTC SYNC pattern. This is useful to tell whether a tape with LTC is shuttling forwards or backwards. In order to minimize the number of accesses required to read or write a block of registers, an auto-increment function is provided. If the MSB of SMPTE2 is written to a one with the address, the address is incremented after each read or write access to SMPTE3. For example, if one wants to read the LTC Read registers, IR0 to IR7, SMPTE2 is written to a 80h. Then read SMPTE3 eight times. The first byte read is from IR0 followed by IR1, etc. Generating LTC The LTC generator transfers data from the LTC Write registers (IR8 to IRF) to the output buffer when the LTC generator is enabled; LTCEN is set to one. Data transfers for subsequent LTC frames occur eight bit times before the end of the LTC frame being output. Remember that a LTC frame ends with a 16 bit SYNC pattern. The LXI interrupt bit in SMPTE0 is set to one when LTC Write register data is transferred to the output buffer. Interrupt Processing Interrupts can be generated from five sources, LTC receiver, LTC generator, video line count, timer and UART. The interrupt status of the first four interrupts, LRI, LXI, VLI and TMI are in the SMPTE0 register. After this register is read, all four interrupts are cleared. It is, therefore, necessary to save the state of the interrupt status and process all active interrupts. A typical program for generating LTC output would first setup the LTC control registers and the LTC bit time registers. Then time code data would be written to the LTC Write register. Once this setup is done the LTC output would be enabled by setting LTCEN to a one. LTC output starts when a LTC SYNC is received. The LTC SYNC source is selected as part of the setup. While the LTC generator is waiting for SYNC, the data in the LTC Write register is transferred to the output buffer. When the transfer is complete the LXI status but is set to a one. The data for the next LTC output frame can then be loaded. The LXI status bit will be set to a one after the data transfer at the end of the first LTC output frame. At this point the LTC Write register is ready to receive data for a third LTC output frame. The UART interrupt status is in the UART0 register. The receive interrupt is cleared by reading the receive data register, UART1. The transmit interrupt is cleared by writing data to the transmit data register, UART1. Reading LTC When LTC data is received, it is placed into a temporary buffer and transferred into the LTC read register (IR0 to IR7) when the last bit of LTC data has been received. It should be noted that the data is transferred before the SYNC pattern has been received. Once the data is in the LTC receive buffer, the ICS2008B 16 ICS2008B Reading VITC With the VITC generator setup properly, when the selected video line starts, the VITC data in the VITC Write buffer, IR20 to IR27, is output. The video line interrupt, VLI in SMPTE0, is provided to allow ample processing time for VITC generation. To read VITC code one must first setup IR30 thru IR33. The VITC Read Line registers, IR30 and IR31, select the video line from which VITC code is to be read. The MSB is the enable for VITC reading. The Read Line field, bits 4 to 0, should be programmed with the desired line number minus ten. So, if line 15 is desired, a 5 should be programmed in the Read Line field. If the read line field is set to 1Fh, this puts the VITC receiver into a scan mode. In scan mode, the VITC receiver looks for a valid time code starting at line 10 for VITC1 or VITC Read Line 1 for VITC2. The scan terminates when a valid time code is received or the line count reads line 41. Burn-in Window The burn-in window can be placed anywhere on the video display. The position of the upper left corner of the window is selected by the values written in IR28 and IR29. IR28 controls the horizontal position. Values from 00h to 71h put the corner in the first half of a video line (starting from the falling edge of HSYNC). Values from 80h to F1h put the corner in the second half of a video line. Any other values will not display the window. Care should be taken not to choose values which put the window in any part of the blanking area. IR29 controls the vertical position. The value written here is the video line number divided by 2. IR32 selects the source and type of video. The GENLOCK ENABLE bit must be set to a one, and the VTRES bit must be set to a zero. The Video Interrupt Line register, IR33 should be set to a line after all VITC read and write lines. This allows all of the VITC receive and generate operations to be complete before processing VITC. The VLOCK bit in the SMPTE1 register indicates whether the ICS2008B is genlocked to the selected video source. Without the VLOCK status set to one, no VITC read will occur. IR3E controls the burn-in window character attributes. It controls the size, normal and large, and the color of the characters and background. IR2A to IR2D, are the registers which control the characters displayed in the burn-in window. When VLOCK is set to one and the control registers are properly initialized, VITC data are received a byte at a time from the video signal and written to the VITC Read registers. At the end of the VITC data frame the CRC byte is checked, and the result reported in bit 5 of IR30 and IR31. In addition to the CRC check, if a full VITC data frame is not received, the NOCODE bit, bit 6, is set to a one. UART The UART is accessed via two directly addressable registers, the command/status register and the data register. On reset, the UART is not operational. The command register must be initialized before the UART will function. Band rates are controlled in UART0 bits 1 and 0. 31.25 kHz supports MIDI communications. 9600 Hz and 38.4 kHz support most serial VTR transport controls. Generating VITC Like reading VITC, IR2E, IR2F, IR32 and IR33 must be setup in order to generate VITC. The VITC Write Line registers, IR2E and IR2F, select the video line to which VITC code is to be written. The MSB is the enable for VITC generation. The Write Line field, bits 4 to 0, should be programmed with the desired line number minus ten. So, if line 12 is desired, a 2 should be programmed in the Write Line field. IR32 selects the source and type of video. The GENLOCK ENABLE bit must be set to a one, and the VTRES bit must be set to a zero. The Video Interrupt Line register, IR33 should be set to a line after all VITC read and write lines. This allows all of the VITC receive and generate operations to be complete before processing VITC. The UART has a four deep FIFO for its receive buffer. This allows for relaxed interrupt latency requirements. In the case of MIDI bit rates, the receiver will not overflow even if the interrupt response delay is 1msec. The UART’s transmitter has a buffer in front of the output shift register so that a byte can be loaded and waiting for the output shifter to be empty. 17 ICS2008B ICS2008B U nits In Inches SYM BO L PLCC 44-PIN PACKAGE M IN M AX A .165 .180 A1 .090 .120 A2 .062 .083 b .013 .021 c .0075 .0125 D /E .685 .695 D 1 /E 1 .650 .656 D 2 /E 2 .291 .319 All Dimensions in Inches N ICS2008B 18 44 pins ICS2008B -HD VERSION HEAT SLUG DOWN SYM BO L M IN N TQFP 44-PIN PACKAGE All dimensions in Millimeters 19 M AX 44 A - 1.20 A1 0.05 0.15 A2 0.95 1.05 b 0.3 0.45 c 0.09 0.20 D 12.00 B A S IC D1 10.00 B A S IC D2 8.00 R ef. E 12.00 B A S IC E1 10.00 B A S IC E2 8.00 R ef. e 0.80 B A S IC L 0.45 0.75 q 0° 7° ccc - 0.08 ICS2008B ICS2008B Document Revision History Rev A (First Release) Started with ICS2008A Rev D Source Document General cleanup for readability. Rev B Correct C2 pin number in Pin Description (pg 3) Call out tieing LFC pin high in Pin Description (pg 3) Added Document Revision History. (pg 20) Added Corporate Contact Information (pg 21) Rev C Added information to PLCC and TQFP Package Diagrams (page 18 & 19) Edited Feature list for clairity (page 1) Updated Ordering Information for Lead Free packages (page 20) Rev D Revised PLCC and TQFP Package Diagrams and dimensions (page 18 & 19) Rev F Added EOL note for ordering information per PDN U-09-01. Rev G removed green parts per PDN U-09-01 Ordering Information Part / Orde r Numbe r M arking Package Shipping Package ICS2008BVLF ICS2008BV 22008BVLF 008BV 44 Pin PLCC Tubes ICS2008BY-10LFT ICS2008BY- 10 22008BY-10LF 008BY- 10 444 4 PPin in TTQFP, Q FP Tape T ubes and Reel ICS2008BY- 10LF 2008BY- 10LF 44 Pin TQFP Lead Free Tubes ICS2008BVLFT ICS2008BVLF 44 Pin PLCC, Lead Free Tape and Reel ICS2008B Lead Free 20 ICS2008B Integrated Circuit Systems, Inc. Corporate Headquarters:2435 Boulevard of the Generals P.O. Box 968 Valley Forge, PA 19482-0968 Telephone: 610-630-5300 Fax: 610-630-5399 San Jose Operations: Web Site: 525 Race Street San Jose, CA 95126-3448 Telephone: 408-297-1201 Fax: 408-925-9460 http://www.icst.com 21 ICS2008B ICS2008B Errata 1. Figure 8 “Self Biased Inputs” Diagram on page 15: a) VDD/2 should be VDD/3 b) 5K should be 35K 2. Add the following notes called “AC Coupling of Internally-Biased Inputs” after “Self Biased Inputs” section on page 15. AC coupling is not recommended when the input is of large voltage swing and/or of low frequency. If AC coupling is attempted in these cases, then great care must be taken that the voltage at the input pin does not go below ground nor be allowed to settle near the threshold value. In such cases, it is recommended that the input pin in question be observed in operation with a high-impedance scope probe. In the case of large voltage swing inputs, the ICS2008B input pin can easily be driven below ground. This is possible because the voltage at the pin will swing around the internally generated bias point. Driving the input pin below ground should never be allowed and can potentially damage the device. In the case of a large input swing, a series resistor can be placed between the coupling capacitor and the input pin to divide down the input voltage and reduce the swing at the input pin. In the case of low frequency signals, the coupling capacitor can become fully charged which will allow the input slew to close to its threshold value, causing any noise to falsely trigger the input. Low duty cycle inputs can have an effect similar to low frequency. A larger coupling capacitor may be required. The case of a low frequency, large amplitude input is especially dangerous because the voltage swing at the input pin is increased by the same amount that the capacitor has charged. As an example of the measures that may need to be taken, a 5V, 30 Hz, 50% duty cycle signal on the Click input can be safely AC coupled to the Click pin by using a 1µF coupling capacitor and a 100K ohm series resistor. The large time constant prevents the capacitor from becoming fully charged and the series resistor, combined with the internal resistor, divides down the input voltage to an acceptable swing so that the input pin is never driven below ground.