FX809 FFSK Modem Recovered Clock CHECKSUM GEN/CHECK VDD BYTE COUNTER Rx IN FFSK DATA REGISTER 1 RECEIVER XTAL/CLOCK CLOCK XTAL SYNC/SYNC DETECT Rx SYNC Detect GENERATOR Rx FREE FORMAT TX OUT FFSK DATA REGISTER 2 TRANSMITTER Recovered Clock VBIAS Rx SYNC Detect TX DATA BUFFER RX DATA BUFFER CS AMP IN Tx Data Ready Rx Data Ready REPLY DATA SYNC PROGRAM LOW – HIGH Enable SERIAL CLOCK Tx Idle Interrupt – + C-BUS INTERFACE VBIAS AND CONTROL LOGIC Rx SYNC Detect COMMAND DATA ADDRESS DECODER WAKE ADDRESS SELECT AMP OUT UNCOMMITTED 8-Bit Parallel Bus CONTROL REGISTER AMPLIFIER V SS Rx SYNC Detect STATUS REGISTER INTERRUPT GENERATOR IRQ Fig 1. FX809 FFSK Modem Brief Description An intelligent, half-duplex, FFSK/MSK modem which operates under “C-BUS” control. In addition this modem provides software selectable checksum generation and error checking, in accordance with MPT1327. The FX809, using Interrupt and Status Register procedures, performs the functions described below: (b) Use the received checksum to calculate the presence of any errors, setting the Status Register accordingly. 3. Make the incoming data directly available, via the Rx Data Buffer (Rx Freeformat), overriding synchronization requirements. In Tx mode the FX809 will: 1. (a) Accept from the host and transmit, 8-bit bytes of data as instructed (Preamble, Sync, Address and data). (b) internally calculate and insert a 2 byte checksum based upon the preceeding 6 bytes of data, or (c) disable the internal checksum generator and continuously transmit the data supplied. 2. Transmit 1 hang-bit and go to Tx Idle when all loaded data bytes have been transmitted. The FX809 achieves Rx input timing by recovering an Rx clock from the incoming data stream. Output tones are timed to the internally generated transmit clock. Filter, register clocks and transmit FFSK tone frequencies are derived internally from the external Xtal or clock pulse input. For compliance with the MPT 1327 Signalling Specification a 4.032MHz Xtal or clock input will be required. In Rx mode the FX809 will: 1. Detect and achieve bit synchronization within 16 bits. 2. (a) Search and detect the user-programmed Sync (or its opposite logic sense) Word and achieve frame sychronization. Data will then be output in 8-bit bytes via the Rx Data Buffer. The FX809 is a low-power 5-volt integrated circuit, incorporating “Powersave” modes to further reduce power requirements. An uncommitted amplifier is provided on chip for general purpose applications within DBS 800. The FX809 is available in 24-pin cerdip DIL and 24pin/lead plastic SMD packages. Publication D/809/5 April 1998 NOTE: All information contained in this data sheet is specified using a 4.032 MHz Xtal, 1200 bps baud rate , Mark and Space frequencies 1200 Hz and 1800 Hz. Pin Number Function FX809 J/LG/LS 1 Xtal: The output of the on-chip clock oscillator. External components are required at this input when a Xtal input is used. See Figure 2, INSET. 2 Xtal/Clock: The input to the on-chip clock oscillator inverter. A Xtal or externally derived clock should be connected here. See Figure 2, INSET. 3 Interrupt Request (IRQ): The output of this pin indicates an interrupt condition to the µController, by going to a logic “0.” This is a “wire-or able” output, enabling the connection of up to 8 peripherals to 1 interrupt port on the µController. This pin has a low-impedance pulldown to logic “0” when active and a high-impedance when inactive. The system IRQ line requires a 'pull-up' resistor to VDD. The conditions that cause interrupts are indicated in the Status Register and are shown below: Tx Idle Rx Data Ready Tx Data Ready Rx SYNC Detect Rx SYNC Detect Interrupt outputs can be disabled by bit 3 of the Control Register. No Internal connection. 4 No Internal connection. 5 6 7 Rx Freeformat: Used in the Rx mode, this input, when a logic “0,” allows received data to be read from the Rx Data Buffer via the Reply Data line without having to acheive byte synchronization (SYNC/SYNC) first. Data will continue to be available after this input goes to a logic “1” until either a SYNC or SYNC Prime bit is set or the the modem set to Tx mode. When held at a logic “1” the modem operates normally. This pin has an internal 1MΩ pullup resistor. NOTE: If this input is held at a logic “0” in the Tx mode, the Rx Data Ready bit in the Status Register may occasionally be set, but not cause an interrupt. If this input is a logic “0” when going into the Rx mode, an Rx Data Ready interrupt may be generated immediately, in this case the first byte of Rx data should be ignored. VBIAS : The internal circuitry bias line, held at VDD/2 this pin must be decoupled to VSS by capacitor C3, see Figure 2. Amp In: The inverting input to the on-chip uncommitted amplifier . 8 Amp Out: The output of the on-chip uncommitted amplifier. 9 10 Rx In: The 1200 baud, 1200Hz/1800Hz, received FFSK signal input. The input signal to this pin must be a.c. coupled via capacitor C4, see Figure 2. No Internal connection. 11 12 VSS: Negative Supply (GND). External Components VDD C5 SEE INSET R4 XTAL XTAL/CLOCK 1 24 2 23 3 22 4 21 5 20 IRQ Rx FREEFORMAT VBIAS R2 SIGNAL IN C6 R3 C7 SIGNAL OUT VSS ADDRESS SELECT SERIAL CLOCK COMMAND DATA 19 7 18 8 17 9 16 10 15 11 14 12 13 Rx IN C4 WAKE CS FX809J 6 VDD REPLY DATA Tx OUT C3 VSS INSET Component XTAL 1 R1 X1 FX809J 2 XTAL/CLOCK C2 C1 V SS Fig.2 External Components Value R1 = 1.0MΩ Note 1: R2 Note 1 R2, R3 and C7 form the gain R3 100kΩ components for the signal; R4 22.0kΩ R3 should be chosen as C1 33.0pF required by the signal input 33.0pF C2 level. C3 1.0µF C4 0.1µF C5 1.0µF C6 33.0pF Note 1 C7 X1 4.032MHz Tolerance: R = ±10% C = ±20% Modem Performance 2 x 10 -2 Bit Error Rate (Logarithmic Scale) 10 -2 Ideal Coherent FFSK Characteristic FX809 Characteristic 10 -3 10 -4 8 6 4 3 2 10 -5 (Linear Scale ) 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 Signal to Noise Ratio (dB) [Bit-Rate Bandwidth] Fig.3 Bit Error Rate vs Signal-to-Noise Ratio Package Outlines Handling Precautions The FX809 is available in the package styles outlined below. Mechanical package diagrams and specifications are detailed in Section 10 of this document. Pin 1 identification marking is shown on the relevant diagram and pins on all package styles number anti-clockwise when viewed from the top. The FX809 is a CMOS LSI circuit which includes input protection. However precautions should be taken to prevent static discharges which may cause damage. FX809J FX809LG 24-pin cerdip DIL (J4) NOT TO SCALE 24-pin quad plastic encapsulated bent and cropped (L1) NOT TO SCALE Max. Body Length Max. Body Width 32.03mm 14.81mm Max. Body Length Max. Body Width FX809LS 10.25mm 10.25mm 24-lead plastic leaded chip carrier (L2) NOT TO SCALE Ordering Information FX809J 24-pin cerdip DIL (J4) FX809LG 24-pin encapsulated bent and cropped (L1) FX809LS 24-lead plastic leaded chip carrier (L2) Max. Body Length Max. Body Width CML does not assume any responsibility for the use of any circuitry described. No circuit patent licences are implied and CML reserves the right at any time without notice to change the said circuitry. 10.40mm 10.40mm CML Microcircuits COMMUNICATION SEMICONDUCTORS CML Product Data In the process of creating a more global image, the three standard product semiconductor companies of CML Microsystems Plc (Consumer Microcircuits Limited (UK), MX-COM, Inc (USA) and CML Microcircuits (Singapore) Pte Ltd) have undergone name changes and, whilst maintaining their separate new names (CML Microcircuits (UK) Ltd, CML Microcircuits (USA) Inc and CML Microcircuits (Singapore) Pte Ltd), now operate under the single title CML Microcircuits. These companies are all 100% owned operating companies of the CML Microsystems Plc Group and these changes are purely changes of name and do not change any underlying legal entities and hence will have no effect on any agreements or contacts currently in force. CML Microcircuits Product Prefix Codes Until the latter part of 1996, the differentiator between products manufactured and sold from MXCOM, Inc. and Consumer Microcircuits Limited were denoted by the prefixes MX and FX respectively. These products use the same silicon etc. and today still carry the same prefixes. In the latter part of 1996, both companies adopted the common prefix: CMX. This notification is relevant product information to which it is attached. Company contact information is as below: CML Microcircuits (UK)Ltd CML Microcircuits (USA) Inc. CML Microcircuits (Singapore)PteLtd COMMUNICATION SEMICONDUCTORS COMMUNICATION SEMICONDUCTORS COMMUNICATION SEMICONDUCTORS Oval Park, Langford, Maldon, Essex, CM9 6WG, England Tel: +44 (0)1621 875500 Fax: +44 (0)1621 875600 [email protected] www.cmlmicro.com 4800 Bethania Station Road, Winston-Salem, NC 27105, USA Tel: +1 336 744 5050, 0800 638 5577 Fax: +1 336 744 5054 [email protected] www.cmlmicro.com No 2 Kallang Pudding Road, 09-05/ 06 Mactech Industrial Building, Singapore 349307 Tel: +65 7450426 Fax: +65 7452917 [email protected] www.cmlmicro.com D/CML (D)/1 February 2002