CMOS MT90710 High-Speed Isochronous Multiplexer Preliminary Information Features ISSUE 1 • Multiplexes eight 2.048 Mbit/s, ST-BUS links onto one serial high-speed 20.48 Mbit/s link • 15.808 Mbit/s clear bandwidth transport • Two 8 kbit/s and one 32 kbit/s oversampled signalling channels • Embedded system timing and frame synchronization • Frame buffer control signals generated on-chip • Check-sum generated on multiplexed frame • Remote synchronization indication • Both master and slave timing mode operation • On-chip reference generation for slave mode synchronization • 4B/5B data encoding/decoding Ordering Information MT90710AP Fibre distributed sytems • Backplane concentrators • Local Area Networks (LANs) STi0 Description The High-Speed Isochronous Multiplexer integrated circuit multiplexes up to eight Serial Telecom (ST-BUS) links onto a single 20 MHz loop to facilitate point-to-point data transport requirements. The MT90710 connects easily with standard Fiber Optic interfaces to form a complete electric to photonic conversion circuit. Optical transmission allows large bandwidth inter-shelf or, in distributed systems, inter-node communication by eliminating multiple data buses, cable inter-connect and attendant driver interfaces. The final result is a simple physical interface free of the radiated emissions and background noise susceptibility problems encountered in copper-wired environments. Overhead Checksum Frame Sync 4B/5B & NRZI Encode PISO MUX To Transmit Driver Amplifier and Fiber Driver Transducer Control Overhead Extract & Insert Error Check NRZI Decode Sync Detect 4B/5B Decode Frame Alignment & Buffer External Memory Control Signals to External PLL MODE0 MODE1 MODE2 F0b C4b E20i RLED LLED C20o POR RESET C4REFo C4o C40i RxDATA FBWE FBOE FBDATA7 FBDATA0 From Receive Pin Diode, Pre-amp and Post-amp Circuits FBADDR7 DEMUX SIPO RECEIVE STo0 STo5 STo6A STo6B STo7 DOUT8K0 DOUT8K1 DOUT32K TxDATA TRANSMIT FBADDR0 STi5 STi6A STi6B STi7 DIN8K0 DIN8K1 DIN32K 84 Pin PLCC 0 °C to +70 °C Applications • January 1995 Figure 1 - Functional Block Diagram 5-3 MT90710 VDD NC RxDATA 34 RLED FBOE 36 MODE2 MODE1 38 MODE0 STo0 40 VDD VSS 42 STo2 STo3 44 STo4 FBWE 46 STo1 48 F0b DOUT32K TxDATA VSS 54 50 IC VDD 52 Preliminary Information 32 POR FBDATA7 VSS 56 30 58 28 60 26 62 24 C4b FBDATA6 64 22 20 68 18 70 16 72 14 NC NC IC C4REFo 10 VSS VDD STo6A STo5 12 8 FBADDR7 NC C20o DOUT8K1 6 4 DOUT8K0 STo7 2 VDD VSS STo6B FBADDR6 84 82 FBADDR5 FBADDR4 FBADDR3 FBADDR2 80 78 FBADDR1 FBADDR0 NC 76 C4o 74 VSS VDD C40i NC FBDATA0 RESET STi2 STi1 FBDATA1 LLED VDD VSS 66 FBDATA2 DIN8K1 STi4 STi3 84 PIN PLCC FBDATA3 STi0 STi6A STi5 VDD VSS STi7 STi6B FBDATA4 DIN32K NC E20i FBDATA5 DIN8K0 NC Figure 2 - Pin Connections Pin Description Pin # Name 1 VSS Power Supply Ground. Nominally 0 volts. 2 VDD Positive Power Supply. Nominally 5 volts. 3 STo7 Serial, 32 Channel, 2.048 Mb/s Link 7 (Output Type 3). Only channels 9 - 31 are available for user data transfer (1.474 Mb/s). Channels 0 - 8 (0.576 Mb/s) are reserved for access to fiber overhead information. Output is active only when the receiver detects the synchronization pattern on RxDATA input stream; output is high impedance during loss of synchronization. 4 DOUT8K0 Asynchronous 8 kHz Signal 0 (Output Type 3). Sourced from the far-end DIN8K0 input. 5 DOUT8K1 Asynchronous 8 kHz Signal 1 (Output Type 3). Sourced from the far-end DIN8K1 input. 6 C20o 7 NC 8 FBADDR7 9 STo6A 5-4 Description 20.48 MHz Clock (Output Type 3). Derived from transmit PLL 40.96 MHz clock divided by 2 (see pin 18). Made available for system use. No Internal Connection. Frame Buffer RAM Address Bit 7 (Output Type 2). Serial, 32 Channel, 2.048 Mb/s Link 6A (Output Type 3). Output is active only when the receiver detects the synchronization pattern on RxDATA input stream; output is high impedance during loss of synchronization. MT90710 Preliminary Information Pin Description Pin # Name Description 10 STo5 Serial, 32 Channel, 2.048 Mb/s Link 5 (Output Type 3). Output is active only when the receiver detects the synchronization pattern on RxDATA input stream; output is high impedance during loss of synchronization. 11 VDD Positive Power Supply. Nominally 5 volts. 12 VSS Power Supply Ground. Nominally 0 volts. 13 C4o 4.096 MHz Clock (Output Type 3). Used by the transmit PLL. This clock is the input C40i (40.96MHz, see pin 18) master clock divided by 10 (inverted) and is fed back to the external PLL circuit as a reference. 14 C4REFo 15,16, 17 NC 18 C40i Transmit 40.96 MHz Clock (Input Type 2). Derived from the transmit PLL. This is the master clock used by the device. 19 STi1 Serial, 32 Channel, 2.048 Mb/s Link 1 (Input Type 1). 20 STi2 Serial, 32 Channel, 2.048 Mb/s Link 2 (Input Type 1). 21 VSS Power Supply Ground. Nominally 0 volts. 22 VDD Positive Power Supply. Nominally 5 volts. 23 STi3 Serial, 32 Channel, 2.048 Mb/s Link 3 (Input Type 1). 24 STi4 Serial, 32 Channel, 2.048 Mb/s Link 4 (Input Type 1). 25 STi5 Serial, 32 Channel, 2.048 Mb/s Link 5 (Input Type 1). 26 STi6A Serial, 32 Channel, 2.048 Mb/s Link 6A (Input Type 1). 27 STi6B Serial, 32 Channel, 2.048 Mb/s Link 6B (Input Type 1). 28 STi7 Serial, 32 Channel, 2.048 Mb/s Link 7 (Input Type 1). Only channels 9 - 31 are available for user data transfer (1.472 Mb/s). Data input on channels 0 - 8 (0.576 Mb/s) is ignored by the device. This bandwidth is reserved for fiber overhead information. 29 E20i Receiver 20.96 MHz Clock (Input Type 2). Extracted clock from the receive data stream. Divided internally by 5 and phase corrected to frame synch pattern to produce internal 2.048 MHz data clock for parsing the receive STi streams. 30 NC No Internal Connection. 31 VSS Power Supply Ground. Nominally 0 volts. 32 NC No Internal Connection. 33 VDD Positive Power Supply. Nominally 5 volts. 34 NC No Internal Connection. 35 RxDATA 36 RLED "Remote Sync" LED Driver (Open Collector, Output Type 3). Drives the "Remote Sync" LED on/off at approximately a 4 Hz rate when the remote interface is not synchronized. Active only when the local interface is synchronized. 37 FBOE Frame Buffer Ram Enable (Output Type 2). Generates a low going strobe during valid RAM read access. 4.096 MHz Reference Clock (Output Type 3). Used by transmit PLL. When in controller mode this clock is derived from the system C4b (4.096 MHz) clock input (see pin 57). When in peripheral mode this clock is extracted from the receive data on the fiber port. No Internal Connection. Receive 4B/5B, NRZI Encoded Serial Data (Input Type 1). 5-5 MT90710 Preliminary Information Pin Description Pin # Name 38 MODE2 Operating Mode Select 2 (Input Type 1). See Table 1. 39 MODE1 Operating Mode Select 1 (Input Type 1). See Table 1. 40 MODE0 Operating Mode Select 0 (Input Type 1). See Table 1. 41 STo0 Serial, 32 Channel, 2.048 Mb/s link 0 (Output Type 3). Output is active only when receiver detects the synchronization pattern on RxDATA input stream; output is high impedance during loss of synchronization. 42 VDD Positive Power Supply. Nominally 5 volts. 43 VSS Power Supply Ground. Nominally 0 volts. 44 STo2 Serial, 32 Channel, 2.048 Mb/s link 2 (Output Type 3). Output active only when receiver detects the synchronization pattern on RxDATA input stream; high impedance output during loss of synchronization. 45 STo3 Serial, 32 Channel, 2.048 Mb/s link 3 (Output Type 3). Output active only when receiver detects the synchronization pattern on RxDATA input stream; high impedance output during loss of synchronization. 46 STo4 Serial, 32 Channel, 2.048 Mb/s link 4 (Output Type 3). Output active only when receiver detects the synchronization pattern on RxDATA input stream; high impedance output during loss of synchronization. 47 FBWE Frame Buffer RAM Write Enable (Output Type 2). Generates a low going strobe during valid RAM write access. 48 STo1 Serial, 32 Channel, 2.048 Mb/s link 1 (Output Type 3). Output active only when receiver detects the synchronization pattern on RxDATA input stream; high impedance output during loss of synchronization. 49 F0b System 8 kHz Reference Frame Pulse (Bi-directional; Input and Output Types 3). When in controller mode this is an input accepting the system reference pulse. In peripheral mode this is an output supplying the system an 8 kHz reference frame pulse. 50 DOUT32K Asynchronous 32 kHz Signal 1 (Open Collector, Output Type 3). Sourced from the far-end DIN32K input. 51 TxDATA 52 VSS 53 IC 54 VDD Positive Power Supply. Nominally 5 volts. 55 POR Power On Reset (Input Type 2). Active low. 56 FBDATA7 57 C4b 58 FBDATA6 Frame Buffer Data Bit 6 (Bidirectional; Input Type 1 and Output Type 2). Data bit 6. 59 FBDATA5 Frame Buffer Data Bit 5 (Bidirectional; Input Type 1 and Output Type 2). Data bit 5. 60 DIN8K0 61 FBDATA4 5-6 Description Transmit 4B/5B, NRZI Encoded Serial Data (Output Type 3). Power Supply Ground. Nominally 0 volts. Internally Connected (Output Type 1). Drives continuous logic 1. Leave open circuit. Frame Buffer Data Bit 7 (Bidirectional; Input Type 1 and Output Type 2). Data bit 7. 4.096 MHz Reference Clock (Bidirectional; Input and Output Types 3). Input used by PLL in controller mode and derived from the system. In peripheral mode this is an output supplying the system 4.096 MHz reference clock. Asynchronous 8 kHz Signal 0 (Input Type 1). Transmitted to the far-end DOUT8K0 output. Frame Buffer Data Bit 4 (Bidirectional; Input Type 1 and Output Type 2). Data bit 4. MT90710 Preliminary Information Pin Description Pin # Name Description 62 DIN32K 63 VDD Positive Power Supply. Nominally 5 volts. 64 VSS Power Supply Ground. Nominally 0 volts. 65 FBDATA3 66 STi0 67 FBDATA2 68 DIN8K1 69 FBDATA1 Frame Buffer Data Bit 1 (Bidirectional; Input Type 1 and Output Type 2). Data bit 1. 70 LLED "Local Sync" LED Driver (Open Collector, Output Type 2). Drives the "Local Sync" LED on/off at approximately a 4 Hz rate when the local interface is not in synchronization. 71 FBDATA0 Frame Buffer Data Bit 0 (Bidirectional; Input Type 1 and Output Type 2). Data bit 0. 72 RESET 73 IC 74 VDD Positive Power Supply. Nominally 5 volts. 75 NC No Internal Connection. 76 VSS Power Supply Ground. Nominally 0 volts. 77 FBADDR0 Frame Buffer RAM Address Bit 0 (Output Type 2). 78 FBADDR1 Frame Buffer RAM Address Bit 1 (Output Type 2). 79 FBADDR2 Frame Buffer RAM Address Bit 2 (Output Type 2). 80 FBADDR3 Frame Buffer RAM Address Bit 3 (Output Type 2). 81 FBADDR4 Frame Buffer RAM Address Bit 4 (Output Type 2). 82 FBADDR5 Frame Buffer RAM Address Bit 5 (Output Type 2). 83 FBADDR6 Frame Buffer RAM Address Bit 6 (Output Type 2). 84 STo6B Asynchronous 32 kHz Signal (Input Type 1). Transmitted to the far-end DOUT32K output. Frame Buffer Data Bit 3 (Bidirectional; Input Type 1 and Output Type 2). Data bit 3. Serial, 32 Channel, 2.048 Mb/s Link 0 (Input Type 1). Frame Buffer Data Bit 2 (Bidirectional; Input Type 1 and Output Type 2). Data bit 2. Asynchronous 8 kHz Signal 1 (Input Type 1). Transmitted to the far-end DOUT8K1 output. Reset Control (Input Type 1). Internally Connected. Serial, 32 Channel, 2.048 Mb/s Link 6B (Output Type 3). Output active only when receiver detects the synchronization pattern on RxDATA input stream; high impedance output during loss of synchronization. Notes: All unused inputs should be connected to logic high or low unless otherwise stated. All outputs should be left open circuit when not used. All output types are CMOS with CMOS logic levels (see DC Electrical Characteristics for Type drive capability). Input Type 1 has TTL compatible logic levels, Type 2 has CMOS compatible logic levels and Type 3 has TTL Schmitt trigger compatible logic levels (see DC Electrical Characteristics). Overview The MT90710 multiplexes multiple Serial Telecom (ST-BUS timing, Figure 7) links onto a single 20 MHz loop to facilitate point-to-point data transport requirements. The MT90710 connects easily with standard Fiber Optic interfaces to form a complete electric to photonic conversion circuit. Optical transmission allows large bandwidth inter-shelf or, in distributed systems, inter-node communication by eliminating multiple data busses, cable inter-connect and the attendant driver interfaces. The final result is a simple physical interface free of the radiated emissions and background noise susceptibility problems encountered in copper-wired environments. 5-7 MT90710 Preliminary Information Frame Pulse Fiber Timeslot 255 0 1 2 3 4 5 6 7 8 9 .......... 246 247 248 249 250 251 252 2 Channel Assignment ST7 Ch0 ST6 Ch0 ST5 Ch0 ST4 Ch0 ST3 Ch0 ST2 Ch0 ST1 Ch0 ST0 Ch0 ST7 Ch1 ST6 Ch1 4B/5B Encoded Data Bit Assignment Bit 9 Bit 8 Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Figure 3 - Fiber Timeslot Assignment The MT90710 provides 15.808 Mb/s clear channel, user bandwidth in both transmit and receive directions. In addition, two 8 kHz sampled signals and one 32 kHz sampled signal are encoded and transported over the loop as additional user bandwidth. These asynchronous signals, in combination with overhead information and clear channel bandwidth produce an aggregate data rate of 16.384 Mb/s. After encoding (4B/5B) the final transmitted baud rate is 20.48 Mbaud. Once compiled, the contents of the transmit data bandwidth is first 4B/5B encoded, then NRZI encoded before it is applied to the transmit fiber interface driver via TxDATA. 4B/5B ensures that the NRZI encoded data will contain a minimum of two transitions per baud. This is sufficient to allow the far end to extract the embedded clock information. As a result of 4B/5B encoding the information bandwidth of 16.384 Mb/s increases to a total baud rate of 20.48 MBaud/s at the fiber interface. Transmit Incoming ST-BUS link data is latched at the mid-bit position of the internal timeslot. Since there is a phase difference between the internal and external timeslots, due to the operation of the PLL, latching occurs at approximately the 3/4 bit position of the external timeslot when in Controller mode. In Peripheral mode data is latched at the midpoint of the timeslot. Asynchronous signals DIN8K0-1 are sampled once per frame (8,000 times per second) and are intended to convey relatively static information where a state transition is not time critical enough that a resolution of one frame is detrimental. Asynchronous signal DIN32K is sampled four times per frame (32,000 times per second) and may be used to transport data at a higher rate than the other two asynchronous inputs. As an example, this sampling rate is sufficient to support 19.2K Baud RS-232 signals (TTL levels) so that remote programming or loop maintenance may be performed. The transmit data interface consists of nine ST-BUS input links and three asynchronously sampled input signals. These are STi0 - STi5, STi6A and STi6B, STi7, DIN8K0, DIN8K1 and DIN32K. Six ST-BUS input links, STi0-5, each provide 2.048 Mb/s transparent transmission bandwidth. With ST6MUX Mode disabled STi6A is also a 2.048 Mb/s link while STi6B is not used (see ST6MUX description). The first nine channels of the STi7 input are ignored leaving the remaining 23 channels for user bandwidth. This allows a total of 15.808 Mb/s clear bandwidth for application use. The first nine (576 kb/s) channels of STi7 are made available for transmitting the three asynchronous signals combined with fiber overhead information. This overhead is automatically compiled in the transmit interface and inserted into these timeslots for transmission over the fiber interface. Overhead information includes a frame synchronization byte, an error count and a checksum calculated on the previous frame of transmitted data. 5-8 MT90710 Preliminary Information ST-BUS input data latched here C20o (Pin 6) Bit Cell C4o (Pin 13) 122 ns FBOE 170.8ns 48.8ns FBWE FBADDR FBDATA WR ADDR RD ADDR RD WR ADDR RD ADDR WR Figure 4 - Frame Buffer Memory Typical Timing Receive The 4B/5B and NRZI encoded data from the receive fiber interface is NRZI decoded and the frame synchronization information is extracted. After 4B/5B decoding the remaining data is frame aligned either to the system frame pulse (when in Controller Mode) or to the extracted frame pulse (when in Peripheral Mode). After alignment, the received data package is disassembled into the clear channel ST-BUS streams, the asynchronous signals and the overhead/status information. When ST6MUX mode is disabled, received 15.808 Mb/s bandwidth is made available on STo0-STo6A and the last 23 channels of STo7. The asynchronous signals are presented on DOUT8K0, DOUT8K1 and DOUT32K while the received overhead information, as well as local status information, is presented on ST07 in channels 0 to 7. Control An external, 40.96 MHz PLL provides the master clock (C40i) for the MT90710. This PLL uses either the system’s C4b clock (pin 57) for reference when it’s in controller mode or the extracted clock from the receive data interface when it’s in peripheral mode. Switching between these two primary references is automatic and under the control of the MODE0-2 pins. The selected reference is fed to the external PLL from the C4REFo output pin. The MT90710 also divides the 40.96 MHz master clock by ten and supplies this secondary reference to the external PLL on C4o for comparison to the primary reference. The PLL creates a 40.96 MHz master clock from a 4.096 MHz reference by multiplying by 10 and attenuates jitter present on the extracted reference. The master clock is divided down to create internal clocks, external ST-BUS clocks (when in peripheral mode) and timeslot counters. Control signals are also created for the transmitter and receiver. The transmitter timeslot counter is synchronized to the backplane frame pulse while the receiver timeslot counter is sync to the extracted synchronization pulse. Frame Buffer To re-align the received data from the fiber interface to the system, or node, a frame reference buffer is 5-9 MT90710 Preliminary Information required. This is implemented using an external 8x8 static RAM (35 ns). Only 256 bytes are used of the 8K total. RAM address and data (FBADDR0-7 and FBDATA0-7) signals are generated along with an output enable strobe (FBOE) and a write enable strobe (FBWE). Mode # Mode 2 Mode 1 Mode 0 ST6MUX Configuration 0 0 0 0 ENABLED CONTROLLER 1 0 0 1 ENABLED PERIPHERAL 2 0 1 0 not used not used 3 0 1 1 4 1 0 0 not used not used 5 1 0 1 not used not used 6 1 1 0 not used not used 7 1 1 1 DISABLED PERIPHERAL ST-BUS Interface The first nine STo7 channels are reserved for overhead information: STo7 Channel 0 1 2 3 Function not available not available Reserved Local error count (most significant byte) Local error count (least significant byte) Reserved Remote error count (most significant byte) Remote error count (least significant byte) synchronization detect (see STo7 channel 8 definition) 4 DISABLED CONTROLLER 5 6 7 8 Table 1 - Operational Mode Select STo7 Channel 8 Definition: B7 Overhead Information B6 Fiber Interface Eight of the 256 fiber channels are reserved for overhead information. These are fiber channels: Channel # Function 0 Frame Alignment 8 Asynchronous signal transfer and synchronization detect 16 Checksum of previous frame 24 Reserved 32 Reserved 40 Reserved 48 Remote error count most significant byte 56 Remote error count least significant byte B5, B4, B3 B2, B1, B0 remote receiver is in frame synch when logic 1 Local receiver is in frame synch when logic 1 Reserved Reserved ST6MUX ST-BUS to Fiber When ST6MUX is enabled the STi6A and STi6B input streams are alternately multiplexed onto the fiber link. (i.e., only half of the bandwidth of each link is utilized). The transmit pattern at the fiber interface is: STi6A-Chan0,STi6B-Chan1,STi6A-Chan2,STi6B-Chan3,..., STi6B-Chan29,STi6A-Chan30,STi6B-Chan31 Multiplexed Stream Chan 0 Chan 1 Chan 2 Chan 3 Chan 4 Chan 5 ..... Chan 28 Chan 29 Chan 30 Chan 31 STo6A Data from STi6A Chan 0 Chan 0 Chan 2 Chan 2 Chan 4 Chan 4 ..... Chan 28 Chan 28 Chan 30 Chan 30 STo6B Data from STi6B Chan 1 Chan 1 Chan 3 Chan 3 Chan 5 Chan 5 ..... Chan 29 Chan 29 Chan 31 Chan 31 Table 2 - ST6MUX Channel Assignment 5-10 MT90710 Preliminary Information CORRECT SYNC SET SYNC = LAST STATE STATE 1 CORRECT SYNC SET SYNC = FALSE INCORRECT SYNC SET SYNC = LAST STATE STATE 2 INCORRECT SYNC SET SYNC = TRUE STATE 0 CORRECT SYNC SET SYNC = TRUE INCORRECT SYNC SET SYNC = FALSE STATE 3 INCORRECT SYNC SET SYNC = FALSE CORRECT SYNC SET SYNC = TRUE Figure 5 - State Diagram Fiber to ST-BUS When ST6MUX is enabled the STo6A and STo6B output streams are comprised of the demultiplexed information received from the fiber link. The received data is duplicated on two channels since the ST-BUS channels support twice the bandwidth of the data from the incoming fiber link. See Table 2. When ST6MUX is disabled the STi6B and STo6B ports are not operational. The STi6A and STo6A ports operate as clear 2.048 MHz links in the same manner as STi/o links 0 to 5. Fiber Loop Synchronization A receiver is declared in synchronization after detection of three consecutive frames containing a valid sync pattern. Once synchronized a receiver will lose sync if a valid sync pattern is not detected in two of four consecutive frames (refer to Figure 5). LED Control The open collector RLED output (pin 36) will cause an LED, pulled up to +5 volts, to flash at approximately a 4 Hz rate when the far-end is out of synchronization but the near-end is synchronized. If the near-end is not synchronized this output is inactive. The open collector LLED output (pin 70) will cause an LED, pulled up to +5 volts, to flash at approximately a 4 Hz rate when the near-end is out of synchronization. Checksum Generator Checksum = 255 ∑ DATA i + C i –1 i=1 Where i-1 is the carry out from the previous operation. The checksum is calculated on all 255 channels except on channel 0 where the frame synchronization code is transported. During this channel the previous checksum is stored and the register initialized for the next calculation. 5-11 5-12 STo0 STo1 STo2 STo3 STo4 STo5 STo6 STo7 STi0 STi1 STi2 STi3 STi4 STi5 STi6 STi7 Frame Buffer Control Signals Frame Alignment and External Buffer Controller Frame Buffer RAM 8K x 8 RxDATA TxDATA Rx Clock Recovery and Bit Regeneration Figure 6 - Typical Fibre Interface Application Clock Interface 4B/5B Decode Error Check Synch Detect Serial-to-Parallel Shift NRZI Decode Parallel-to-Serial Shift 4B/5B and NRZI Encode Framesynch Fibre Receiver and Amplifier AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAAAAAA AAAA AAAAAAAA AAAA AAAAAAAA Transmit Clock PLL DEMUX MUX Checksum AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAAAAAA AAAAAAAA AAAA AAAAAAAA I N T E R F A C E S Y S T E M Transmit Amplifier and Fiber Transmitter MT90710 Preliminary Information MT90710 Preliminary Information Absolute Maximum Ratings* Parameter Symbol Min Max Units VDD - 0.3 7 V VSS - 0.3 VDD + 0.3 V +/- 50 mA + 150 °C 1 DC Supply Voltage 2 Input Voltage Vi 3 DC Input Current Ii 4 Storage Temperature Tstg - 65 * Exceeding these figures may cause permanent damage. Functional operation under these conditions is not guaranteed. Recommended Operating Conditions Characteristics Sym Min Typ Max Units 1 Input Voltage VDD 4.5 5.5 V 2 Operating Temperature TOP 0 +70 °C Test Conditions DC Electrical Characteristics - Voltages are with respect to ground (VSS) unless otherwise stated. Characteristics operating Sym 1 Supply Current 2 Input HIGH voltage (TTL) VIHT 3 Input LOW voltage (TTL) VILT 4 Input HIGH voltage (CMOS) VIHC 5 Input LOW voltage (CMOS) VILC 6 Positive threshold (schmitt) V+ 7 Negative threshold (schmitt) V- 8 Hysteresis VH 9 Input leakage current IIH/IIL 10 High level output voltage VOH 11 Low level output voltage VOL 12 Output Current IO1 IO4 IO12 13 High impedance leakage IOZ 14 Output capacitance Co 15 Input capacitance Ci Min IDD Typ‡ Max Units 230 276 mA 2.0 V Input Type 1 V Input Type 1 V Input Type 2 0.3VDD V Input Type 2 2.0 V Input Type 3 V Input Type 3 V Input Type 3 µA VDD=5.5V, VIN=VSS to VDD V All output types @ max I V All output types @ max I 0.8 0.7VDD 0.8 0.5 150 3.7 0.4 1 4 12 7 Test Conditions mA mA mA Output Type 1 Output Type 2 Output Type 3 20 µA VDD=5.5V, VIN=VSS to VDD 20 pF 20 pF ‡ Typical figures are at 25°C and are for design aid only: not guaranteed and not subject to production testing. 5-13 MT90710 Preliminary Information AC Electrical Characteristics† - ST-BUS Timing Voltages are with respect to ground (VSS) unless otherwise stated. Characteristics Sym Min Typ‡ Max Units 1 Frame Pulse width tF0iW 2 Frame Pulse setup time tF0iS 10 190 ns 3 Frame Pulse hold time tF0iH 20 190 ns 4 STo delay Active to Active tDAA 100 ns 5 STi setup time tSTiS 20 ns 6 STi hold time tSTiH 20 ns 7 Clock period tC4i 200 244 300 ns 8 CK Input Low tCL 85 122 150 ns 9 CK Input High tCH 85 122 150 ns 10 ns 10 Clock Rise/Fall Time 244 Test Conditions ns 45 tr,tf CL=150 pF † Timing is over recommended temperature & power supply voltages (VDD=5V±10%, VSS=0V, TA=0 to 70°C). ‡ Typical figures are at 25°C and are for design aid only: not guaranteed and not subject to production testing. tF0iW 2.0V F0i 0.8V tC4i tF0iH tCH tCL 2.0V C4i 0.8V tf tF0iS tr tDAA STo 2.0V 0.8V Ch. 31 Bit 0 Ch. 0 Bit 7 tSTiS STi 2.0V 0.8V Ch. 31 Bit 0 Ch. 0 Bit 6 tSTiH Ch. 0 Bit 7 Figure 7 - ST-BUS Timing 5-14 Ch. 0 Bit 5 Ch. 0 Bit 6 Ch. 0 Bit 5