MSM7712 Wireless LAN Baseband Controller DESCRIPTION The MSM7712 is the first release in a series of wireless LAN baseband controllers, designated .XI (a suffix of the IEEE P802.11 protocol). The MSM7712 integrates the baseband physical layer and the lower MAC layers into a single IC that supports specific draft standards of the P802.11 specification. The architecture targets optimum integration with maximum user flexibility, providing a migration path to low-cost module handsets and access points. In accordance with all three P802.11 media, the MSM7712 directly supports frequency hopping (FH), spread spectrum, direct-sequence spread spectrum, and infrared protocols., A board-level system contains the MSM7712, a radio, a 16-bit processor, and buffer memory ICs. The MSM7712 provides a seamless interface to the radio, hoist, processor, and memory subsystems. The device directly interfaces with the PCMCIA R2.1 and ISA bus, with support for 16-bit data transfers. The device can control antenna select, synthesizer programming, and power-save modes. The MSM7712 provides FH PLPC framing, with the FH modem on-board. A bypass mode allows support for other standards. MSM7712 firmware is available from Oki Semiconductor. Portable handheld systems inherently require minimal current dissipation during operation and standby modes. The MSM7712 offers low power consumption via its implementation of a 3-V core. Either 3-V or 5-V I/O are available for optimal RF and host-interface design. The MSM7712 wireless LAN baseband controller is manufactured in Oki’s advanced Si-gate 0.5µm CMOS process for the best possible low-power performance. FEATURES • Support for specific IEEE P802.11 wireless LAN draft standards • Suitable for low-cost stations and access points • PCMCIA compliant (version 2.1) interface supporting 16-bit data transfers • On-chip radio modem for high-throughput data transfers • Interface to radio providing antenna select, power control, synthesizer programming • Processor interface support for 80C86, 80C186, V33, and V53A • On-chip multi-port memory controller on chip for local shared memory and simplified design construction • E2PROM interface to download host interface configuration data and provide non-volatile card parameter storage • Low-power mode to minimize power dissipation in batter applications. • 5-V external and 3.3-V core operation • 144-pin LQFP package, suitable for PCMCIA Type II Cards (LQFP144-P-2020-0.50-K) Oki Semiconductor 1 ■ MSM7712 ■ ––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––– BLOCK DIAGRAM Figure 1 shows a typical WLAN card. The MSM7712 provides a direct connection to a host interface, processor, radio, shared memory, and configuration E2PROM. Optional additions are a RAM for processor code. MSM7712GS-K PHY Layer, Radio Interface Radio Combined 1 & 2 Mbps Modem Processor RAM (optional) 802.3 MAC Protocol Controller Host Computer PCMCIA Interface Processor Interface Memory Controller E2PROM Interface Processor Shared RAM (32k~128kx16) E2PROM Figure 1. MSM7712 Block Diagram & Typical WLAN Card 2 Oki Semiconductor –––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––– ■ MSM7712 ■ PACKAGE DRAWING 1.25 TYP 0.22 ±0.05 0.5 0.10 M 108 73 109 72 20.0 ±0.1 SQ 22.0 ±0.2 SQ 1.25 TYP LQFP144-P-2-2-0.50-K PIN 1 INDEX (Mirror Finish) 144 37 1 36 0.17 ±0.05 Seating Plane 0.10 0~0.25 0~10° 1.4 ±0.05 1.7 Max 1.0 ±0.2 0.5 TYP Dimensions in millimeters Oki Semiconductor 3 ■ MSM7712 ■ ––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––– 144 143 142 141 140 139 138 137 136 135 134 133 132 131 130 129 128 127 126 125 124 123 122 121 120 119 118 117 116 115 114 113 112 111 110 109 RA15 RA16 DIAG6 DIAG5 DIAG4 DIAG3 DIAG2 DIAG1 DIAG0 RXD VSSO VDDO IFD5 IFD4/SLICE IFD3 IFD2 IFD1 IFD0 RSSITN ANT RADPWR TXC2 TXC1 RXC1 LKDET SYNLEN EECS SYNDAT/EEDIO SYNCLK/EESK DACEN RCK VSSO VDDO PST0 PST1 PST2 PIN CONFIGURATION 108 107 106 105 104 103 102 101 100 99 98 97 96 95 94 93 92 91 90 89 88 87 86 85 84 83 82 81 80 79 78 77 76 75 74 73 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 RD13 RD14 RD15 HIOIS16N HD10 HD2 HD9 HD1 HD8 HD0 HA0 HA1 HREG HA2 HPACKN HA3 VDDC VSSC VSSO VDDO HWAITN HA4 HRST HA5 HA6 HA7 HIREQN HWEN HIOWRN HA8 HIORDN HOEN HCE2N HCE1N HD15 HD7 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 RA14 RA13 RA12 RA11 RA10 RA9 RA8 RA7 RA6 RA5 RA4 RA3 RA2 RA1 RA0 SCK VDDO VSSO RWRN RCELN RCEHN RD0 RD1 RD2 RD3 RD4 RD5 RD6 RD7 RD8 RD9 RD10 VDDO VSSO RD11 RD12 Figure 2. 144-Pin Plastic TQFP Pin Assignment 4 Oki Semiconductor PCLK PRESETN PINTN PCLKOUT PUBE PCSN PREAD PREADYN PD17 PD16 PD15 PD14 PD13 PD12 PD11 PD10 PD9 PD8 PD7 PD6 PD5 PD4 VSSO VDDO PD3 PD2 PD1 PD0 HD3 HD11 HD4 HD12 HD5 HD13 HD6 HD14 –––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––– ■ MSM7712 ■ INTERFACE DESCRIPTIONS Processor Interface Most applications (e.g. PC add-in cards) require a local processor to handle the higher layers of the IEEE 802.11 protocol. The host computer typically runs a NDIS or ODI driver that communicates to the local processor via shared memory and interrupts. The local processor performs the higher layers of the IEEE 802.11 MAC protocol while the MSM7712GS-K performs the lower layers of MAC and the PHY under control of the local processor. The MSM7712 can be configured to operate with 80C80 (V30) and 80C186 processor types. The processor configuration P_CONF is determined from the level of the PD lines during the MSM7712 reset. Designers should consult the appropriate processor datasheets and this section to understand how the processor interface works. No external circuitry is required between the processor and the MSM7712. Table 1 specifies the connection of various processor signals to the MSM7712. Processor Options MSM7712GS-K P_CONF 80C86, V30 (Max mode) 80C186 1 2 PA[17:16] A[17:16] AD[17:16] PD[15:0] AD[15:0] AD[15:0] PST2 BS2 S2 PST1 BS1 S1 PST0 BS0 S0 - - PREAD PUBE UBE BHE PCLKOUT - CLKOUT PREADYN READY SRDY INT INT0 RESET RES CLK X1 PINTN PRESETN PCLK The output signal PREADYN, PINTN, PRESETN are active low or high to suit the different processor requirements P_CONF option 1 provides an interface to the 80C86 or V30 processor. The processor must be set to maximum mode and a device with a 50% mark/space clock ratio at 16MHz and must be used (assuming a CSCK of 32 MHz). P_CONF option 2 provides an interface to the 80C186 processor family with a 32 Mhz oscillator input. All other values of P_CONF are reserved and should not be used. Oki Semiconductor 5 ■ MSM7712 ■ ––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––– Processor Interface Signal Descriptions Pin Name Direction Description PA[17:16] Input Provides the high address pins to the MSM7712. The usage depends on the shared memory size. The address space usage of the MSM7712 is 256 kbytes comprising MSM7712 registers and shared RAM. PCSN Input Provides a processor chip select to the MSM7712. From reset, this pin is ignored and all processor accesses use the MSM7712. The pin can then be configured by software to be active high or active low. PD[15:0] Bidirectional Provides the data bus and low addresses. The 80C86 and 80C186 processors have a multiplexed address/ data bus and are connected directly to PD [15:0]. The MSM7712 configuration is provided on these pins during reset. During reset (HRST asserted), the processor is reset and these pins are configured as input pins. The configuration is set by weak pull-up and pull-down resistors on PD [7:0]. Following reset and when the processor is not reset, the bus operates normally. See the Configuration Section for detailed options. PST[2:0] Input Provides Processor Status to the MSM7712. Typically this differentiates between memory and I/O reads and writes. PUBE Input In conjunction with PD[0], this signal provides a decode of even byte, odd byte, or word accesses by the processor. The MSM7712 registers are accessed as words and the processor and shared RAMs can be accessed as bytes or words. PCLKOUT Input Within a 80C186 processor-based system, CLKOUT should be connected to PCLKOUT pin. This is required such that PREADYN timing requirements relative to CLKOUT are met. PREADYN Input This pin signals the processor that the bus cycle is complete. The only accesses that potentially require wait states are those to the shared RAM. The shared RAM is accessed by the MSM7712 host (via PCMCIA) and processor on a priority basis. This means the shared RAM may be busy when the processor requests an access and hence wait states are inserted until the shared RAM is available. PINTN Output One interrupt is provided from the MSM7712 to the processor. A fixed interrupt vector is provided on the data bus for interrupt acknowledge cycles. Although described as active low (by the xxxN convention), the pin state is active high or low depending on the processor selected. PRESETN Output The processor is reset via the host computer with this signal. From card reset, the processor is typically held in reset until the program code is downloaded from the host. Although described as active low (by the xxxN convention) the pin state is active high or low depending on the processor selected. PCLK Output The processor clock is provided by the MSM7712. From power up PCLK is set at SCK divided by 8. A register programs PCLK to be from SCK to SCK divided by 8. The PCLK frequency selection allows a processor to operate at either low power or maximum performance. Within a 80C186 system, the processor is synchronized to the MSM7712 by monitoring the processor CLKOUT signal and skipping PCLK periods if necessary. All processor types must use this clock. The MSM7712 expects the processor bus interface timing to be synchronized with this clock signal. Note: SCLK is typically 16 MHz or 32 MHz depending on which modem and processor is being used. PREAD 6 This pin is reserved for future product enhancements. Oki Semiconductor –––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––– ■ MSM7712 ■ Shared RAM Interface Local memory is provided for packet buffer and processor code and data. Memory size is flexible from 32K words to 128K words to support a range of applications (e.g. low-cost stations to high performance access points). Memory is word-sized to allow maximum performance in packet transfer rate. The design allows the use of word-wide RAMs or a pair of byte-wide RAMs. The MSM7712 and host computer access shared RAM in words only. The processor can access the RAM as odd or even bytes in addition to words. For minimal cost applications local processor code may reside in shared memory. This may affect the processor speed because accesses to shared memory may have wait states inserted. The RAM access time is (1.5 clock cycles less 18 ns). Hence, with a MSM7712 clock (RCLK) of 16MHz, the RAM requires an access time better than 75 ns. Shared RAM Interface Signal Descriptions Pin Name Direction Description RA[16:0] Output The RAM address is provided by these pins. A maximum address size of 128K words is supported. RD[15:0] Bidirectional The RAM data is provided on these pins. Word or byte operations are supported. When the shared memory is not in use the data bus is output to prevent a floating data bus consuming power. RCELN Output When asserted, a low byte (or word) shared RAM cycle is active. RCEHN Output When asserted, a high byte (or word) shared RAM cycle is active. RWRN Output When asserted, a write cycle is required. When deasserted a read cycle is required. This signal remains valid before and while RCELN and RCEHN are asserted. Oki Semiconductor 7 ■ MSM7712 ■ ––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––– E2PROM Interface E2PROM support is provided to allow for non-volatile storage of the host interface configuration (e.g. PCMCIA CIS table) and wireless LAN parameters (e.g. local IEEE address, radio parameters). The design supports a 64, 128 or 256 byte E2PROM (e.g. 93C46,93C56, or 93C66 types). V MSM7712 EECS SYNCLK/EESK SYNDAT/EEDIO CS SK DI DO V 93c46 93c58 94s66 V Figure 3. E2PROM Connections to MSM7712GS-K The local processor can access the E2PROM for reads, writes and control functions. This is used to initialize the E2PROM and provide card parameter storage. Following a reset by the host processor, the 64 or 128 bytes of E2PROM contents are automatically read to shared RAM to provide the configuration information for the host interface. E2PROM Interface Signal Descriptions Pin Name Direction Description EEDIO Bidirectional This is a bidirectional data signal for the E2PROM. It is connected directly to DI of the E2PROM, and to DO via a resistor (see E2PROM application notes and Figure 3). EECS Output This signal is connected to CS of the E2PROM to provide the chip select. EESK Output This signal is connected to SK of the E2PROM to provide the clock. The clock rate is RCK divided by 64 (250 kHz with RCK at 16 MHz). Host Interface (Between Adapter Card and Computer or Laptop) The 16-bit PCMCIA interface is fully supported by the MSM7712 with no additional logic. Access to attribute memory (the CIS configuration data) and I/O memory (host registers) are provided. In normal operation, access to the baseband controller registers and shared buffer memory is via a small number of I/O addresses. This requires minimum support in memory and input/output from the host computer. The signals are defined in the PCMCIA standard. Note that the PCMCIA bus timing is independent of the system clock timing. PCMCIA Interface MSM7712GS-K Pin Type H_CONF PCMCIA 0 HA[8:0] Input A[8:0] HD[15:0] Bidirectional D[15:0] HWEN Input WEN HOEN Input OEN HIORDN Input IORDN 8 Oki Semiconductor –––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––– ■ MSM7712 ■ PCMCIA Interface (Continued) MSM7712GS-K HIOWRN Pin Type Input PCMCIA IOWRN HCE1N Bidirectional CE1N HCE2N Bidirectional CE2N HREG Input Reg HWAITN Output WAITN HIOIS16N Output IOIS16N HPACKN Output PACKN HRST Input RST HIREQN Output IREQN Host Interface Signal Descriptions Pin Name Direction Description HA[8:0] Input An attribute address range of 512 even bytes accesses is supported. An I/O space of 4 words is used (i.e. HA[2:0] is used and HA[8:0] is not used). HD[15:0] Bidirectional Attribute memory is standardized to even byte accesses only. Input/Output memory is defined as word accesses only (to maximize packet transfer rates). HOEN, HWEN, HIORDN,HIOWRN, HCE1N, HCE2N, HREG Input These signals provide the chip selects, read strobes, write strobes as defined in the PCMCIA standard HPACKN, HIOIS16N Output These signals provide the chip selects, read strobes, write strobes as defined in the PCMCIA standard HRST Input The card reset is provided by HRST. HRST must be asserted for a period of time from power up to allow the oscillator to settle. The MSM7712 is set to a default state while HRST is asserted and SCK is available. From HRST being deasserted the MSM7712 must download the CIS table from the E2PROM to SRAM before the reset procedure is considered complete. HIREQN Output HIREQN operates as the RDY/BSY line until the card is configured and hence remains low until the reset process is complete (as defined in the PCMCIA standard). Once reset is complete, HIREQN functions as a levelsensitive interrupt to the host. HWAITN Input Wait states are potentially required when the host accesses the shared memory (to transfer packet data). Internal registers require no wait states. Oki Semiconductor 9 ■ MSM7712 ■ ––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––– Radio Interface The radio interface supports simple, flexible control of the radio and its synthesizer. The control signal timing is programmable by the processor. Figure 4 shows the connection to a typical radio architecture. Radio MSM7712 LNA RADPWR RXC1 SLICE RXD Disc RSSITH CSN DAC D T/R Switch Diversity Switching + - DACEN SYNCLK SYNDAT SYNLEN LKDET 1LO 2LO PA DAC IFD[5:0] TXC1 TXC2 ANT Figure 4. Typical FH Radio Interface Radio Interface Signal Descriptions Direction Description RXC1 Pin Name Open-collector/drain Output When asserted reception is enabled. RXC1 is always asserted during reception. This signal is programmable to be open-collector (active low) or open-drain (active high). TXC, TXC2 Open-collector/drain Output When asserted transmission is enabled. Both signals are programmable to be open-collector (active low) or open-drain (active high). Transmit is only activated following a receive (where Clear Channel Assessment is performed). The timing of TXC1 and TXC2 at the start of a transmit is programmable from the deassertion of RXC1. RXC2 is typically used for TX Power Amplifier switching, and its assertion depends on the power control mode selected in the MSM7712. RADPWR Open-collector/drain output This pin is asserted to power up the radio circuitry (i.e. local oscillators) for reception. The pin is programmable to be open-collector (active low) or open-drain (active high). ANT Open-collector output This pin selects one of two antennas for transmission or reception. SLICE Open-collector/drain output This control pin determines the response time constant of an analog data slicer when using the internal modem with an analog data slicer circuit (options MSEL-0 or 1). This pin is programmable to be open-collector (active low) or open-drain (active high). The pin is asserted when CCA has determined a valid IEEE 802.11 GH signal (preamble is detected). 10 Oki Semiconductor –––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––– ■ MSM7712 ■ Radio Interface Signal Descriptions (Continued) Pin Name Direction SYNCLK, SYNDAT, SYNLEN Open collector LKDET Input DACEN Open-collector RSSITH Input Description These signals provide the interface to the radio synthesizer to select the transmit/receive carrier. Many synthesizers are supported by a flexible architecture. The data is output on SYNDAT ready for the rising edge of SYNCLK. SYNLEN is asserted during the programming, and the data is latched on the rising edge of SYNCLEN. SYNCLK is clocked at RCK divided by 2. SYNCLK and SYNDAT are also used to program a serial DAC used for TX power control, CCA threshold and RSSI measurement (see below). The synthesizer is programmed when the radio is idle. The RSSI and CCA threshold DAC is used at the start of receiving a packet. The TX power DAC is programmed at the start of transmitting packet. The radio provides indication of being in lock with LKDET. This input is active high or low (programmable), pulse sensitive, and latched so that both pulsed and steady out-of-lock signals are recognized. Glitches shorter than 2 RCK periods are ignored. Transmission is prevented when the synthesizer is out-of-lock For TX power control, CCA threshold and RSSI measurement, data is also clocked into a serial DAC (10/12 bit type e.g. MAX515/MAX539) using the SYNCLK and SYNDAT lines as described above, except that DACEN is asserted during the programming, and the data is latched on the rising edge of DACEN. RSSITH is an input from a threshold comparison of the analog RSSI signal from the radio with the DAC output. It is high when the received signal exceeds the programmed threshold. This performs two purposes: • A minimum threshold of RSSI can be set before enabling the demodulator for CCA to reduce power. • Once a valid receive signal is determined (CCA invalid) the RSSI can be measured with the external comparator/DAC and a SAR within the MSM7712. The RSSI measurement is performed for internal and external modem options when CCA is determined. The same DAC can be used for both TX power control, RSSI threshold and RSSI measurement RCK Output A clock to the radio is provided on this pin. The clock is derived from SCK when RADPWR is asserted, with fixed division ratio of one or two (selected by post-reset configuration SCK_CONF). RCK is typically 16MHz for the radio synthesizer reference. Radio Analog RSSI Power Control MSM7712 + - RSSITH CSN DAC D DACEN SYNDAT SYNCLK Figure 5. Connection of Serial DAC for Power Control and RSSI Oki Semiconductor 11 ■ MSM7712 ■ ––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––– MODEM Interface The MSM7712 provides FH PLPC framing and the FH modem as defined by the IEEE 802.11 specification.The radio synthesizer control pins are used for all modem options. A diagnostic port is provided when the internal modem is used. Several options are provided by the internal FH modem selected by the PHY_VER[MSEL] register bits. The following table shows the pin usage for various modem options. Modem Options and Pin Connections [1] Modem Interface FH Mbps (Low Cost) FH 1/2 Mbps (Normal ADC) FH 1/2 Mbps (Delta ADC) MSEL 1 2 3 IFD[] IFD[5:0] to TXIF DAC IFD[4] carries SLICE on RX IFD[5:0] to TXIF DAC and IFD[3:0] from RXADC IFD[5:0] to TXIF DAC (also used for Delta ADC) RXD Baseband RX data from radio Recovered data (Debug out) Input from Delta ADC comparator 1. All modem signals are synchronized to RCK. Modem Interface Signal Descriptions Pin Name Direction Description IFD[5:0] Bidirectional If MSEL=1 (low cost for 1Mbps modem), IFD[5:0] are used to drive a 6-bit DAC at 32 MHz to provide the modulated transmit IF signal at 24 MHz. They are set to the DAC mid-value during receive. It is anticipated that a resistor ladder DAC will be used. If MSEL=2,3, (1/2 Mbps modem), IFD[5:0] are used to drive a 6-bit DAC at 32 MHz to provide the modulated transmit IF signal at 24 MHz. If MSEL=2 (1/2 Mbps modem, normal ADC) a 4-bit ADC (e.g. CA3304 type) provides digitized demodulated data at 16 MHz as input to the baseband controller on pins IFD[3:0] during receive. The ADC outputs must only be enabled during receive (e.g. by connecting RXC1 to the ADC output enable pin). If MSEL=3 (1/2 Mbps modem, delta ADC), a comparator is used to compare the value of the transmit IF DAC output to the receive demodulated signal, performing a tracing delta ADC function. The same 6-bit DAC (but at 16 MHz) is used on IFD[5:0] as during transmit, and the comparator input is connected to the RXD pin RIFD[5:0] Bidirectional With MSEL=2 (1/2 Mbps modem, normal ADC) a 4-bit ADC (e.g. CA 3304 type) provides digitized demodulated data at 16 MHz as input to the baseband controller on pins IFD (3:0) during receive. The ADC outputs must only be enabled during receive (e.g. by connecting RXC) to the ADC output enable pin. RXD Input When MSEL=1 (low-cost 1 Mbps modem), the RXD pin is used for baseband data input from a radio which has a built-in analog data slicer. The MSM7712 has a clock recovery circuitry to synchronize to the incoming data. The recovered clock is output on a diagnostic pin for test purposes. When MSEL=3 (1/2 Mbps modem, delta ADC), the delta comparator is input on this pin. The recovered clock from the demodulator is output on a diagnostic pin for test purposes. DIAG[6:0] Output Various signals are provided on these pins as diagnostic aids. The registers PHY_CTL[DIAG] and DEM_CTL0[DTST] select what signals are provided on these pins. 12 Oki Semiconductor –––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––– ■ MSM7712 ■ General Signals General Signal Descriptions Pin Name Direction Description SCK Input The system clock to the MSM7712 is provided by this pin. The clock must always be active (i.e. when reset is asserted). The WLAN card operates synchronously to this clock. The MSM7712 and radio operate at SCK/2. The internal modem operates at SCK (32 MHz). The processor operates from a division of SCK (divide by 1 to divide by 8) depending on a register (GLOB_CTL, see Programmers Reference) in the MSM7712. This signal is output as PCK. VCSS, VPSS Power These pins serve as ground for the core logic and I/O pads. VCDD Power This pin serves as power to the core at 3-V nominal. VPDD Power These pins serve as power to I/O pads and can either be 3-V or 5-V nominal. Test TEST mode is activated when HRST and PST2 are both active low (an illegal state) in normal operation. The MSM7712 operates normally when TEST is not asserted. When asserted, the following test modes are selected using processor data pins PD[1:0]. Test Select Options PD[1] PD[0] Test Description 0 0 Scan Internal manufacturing scan test providing greater than 95% fault coverage. The scan select pin is PST0. 0 1 Hi-Z All output pins are set to high impedance. This test allows external tester to drive MSM7712GS-K pins. 1 0 PinConn All bidirectional, 3-state (except processor) and output pins are set to output and input pins determine state of output pins. This test ensures connectivity of the MSM7712G-K to the PCB 1 1 Reserved MODEM SPECIFICATION The following two subsections describe modulator and demodulator specifications. Modulator The MSM7712 features an internal digital 24 MHz IF CP-FSK modulator. There are two modes of modulator operation: • 1 Mbit/s, 2-ary CP-FSK • 2 Mbit/s, 4-ary CP-FSK Deviations can be set independently for both modes. Modes switch phase continuously in a single clock cycle. • 1 Mbit deviation: 1MDEV = N x 326 /4096 Hz • 2 Mbit deviation: 2MDEV = N x 3 x 326/4096 Hz where N=0.63. Digital on/off ramping from 0 ~ 24 µs of the modulator output power may be added under register control Oki Semiconductor 13 ■ MSM7712 ■ ––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––– Modulator radio requirements are: • 6-bit DAC, clock at 32 MHz (offset binary). • Anti-alias filtering to extract the 24-MHz alias (24 MHz IF will be -10 dB on 8 MHz fundamental from DAC output) • Gaussian filtering, to translate CP-FSK into G-FSK, in accordance with the IEEE 802.11 specification (SAW filter at 240 MHz IF recommended) Demodulator The MSM7712 features a digital baseband demodulator, requiring an external discriminator. The MSM7712 supports two modes: • 1Mbit/s 2-ary FSK • 2 Mbit/s 4-ary FSK. Both modes require a 1-Mbit preamble of 80 bits of reversals and 16 bits UW for acquisition of carrier and timing. The modem can then be switched to 2 Mbit/s if following headers require. Features of the demodulator include: • Diversity switching control for two antennas. • RSSI threshold wake-up of demodulator The demodulator offers three possible interfaces to a limiter/discriminator radio. The supported interfaces are: • Analog data slicer (1Mbit/s only) • Post discriminator 4-bit ADC (offset binary) • Post discriminator 1-bit ADC (provisional) The demodulator’s radio requirements are: 1 Mbit: 20 dB S/N from discriminator 10-5 BER (802.11 specifies sensitivity of 10-5 for 80 dBm) 2 Mbit: 30 dB S/N from discriminator 10-5 BER (802.11specifies sensitivity of 10-5 for 75 dBm) Discriminator linearity of ±5% required for specified 2 Mbit/s operation. 4-bit discriminator-to-ADC ranging, to cover approximately ±360 KHz. Carrier acquisition for analog slicer option within 4 µs, yielding a duty cycle better than 60:40 for a square wave (demodulation provides signal for carrier lock switch once preamble detected. • RSSI threshold decision within 4 µs of antenna switching. • 3-state ADC output during transmit (bus is shared with TxDAC). • • • • • 14 Oki Semiconductor –––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––– ■ MSM7712 ■ ELECTRICAL CHARACTERISTICS Absolute Maximum Ratings [1] Parameter Symbol Power Supply Voltage Core VCDD Power Supply Voltage Pad VPDD Input Voltage VI Output Voltage VO Input Current per Pad II Output Current per Pad Storage Temperature Condition Rating Unit -0.3 to 4.6 -0.3 ~ 7 V -0.3 ~ VDD+0.3 TJ = 25 °C VSS = 0V -0.3 ~ VDD+0.3 -10 ~ +10 mA IO -10 ~+10 mA TSTG -65 ~ 150 ˚C 1. Permanent device damage may occur if ABSOLUTE MAXIMUM RATINGS are exceeded. Functional operation should be restricted to the conditions as detailed in the operational sections of this data sheet. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. Operating Range VSS = 0 V Range Unit Power Supply Voltage Core Parameter VCDD Symbol 2.7 ~ 3.6 V Power Supply Voltage Pad VPDD 4.5 ~ 5.5 V Ambient Temperature Ta -40 ~ +85 ˚C Oscillator Frequency SCK 40 MHz DC Characteristics VPDD = 4.5 ~ 5.5 V, VPSS = 0 V, TJ= -40 ~ +85 ˚C Parameter Symbol Condition [1] Min Typ Max “H” level Input Voltage VIH TTL Input 2.0 - VPDD+0.3 Unit V “L” Level Input Voltage VIL TTL Input -0.3 - 0.8 V “H” Level Output Voltage VOH IOH = 100 µA VPDD – 0.2 2.4 - - V “L” Level Output Voltage VOH - - 0.2 0.4 V Standby Current (Core) ICORE VDD = 3 V, RST asserted, SCK active - 56.5 - mA Standby Current (Pad) IPAD VDD = 5 V, RST asserted, SCK active - 9.3 - mA Normal Current (Core) ICORE VDD = 3 V, RST asserted, SCK active - 58.4 - mA Normal Current (Pad) IPAD VDD = 5 V, RST asserted, SCK active - 30.2 - mA 1. All inputs are CMOS thresholds. All outputs, 3-states, open-drains, open-collectors are rated at 2 mA drive. All bidirectional pins are rated at 4 mA drive. Oki Semiconductor 15 ■ MSM7712 ■ ––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––– AC Characteristics Processor Interface The MSM7712 is designed to operate with the V80C86, V33, V53A, and 80C186 processors. Refer to the appropriate processor data sheets for detailed information. Host Interface The MSM7712 meets the timing requirements of the PCMCIA interface. Wait states are used to provide the access times to the shared RAM when required. Shared Memory Interface Shared Memory Timing [1] Min. Typ. Max. tS(RCE) Parameter Setup time of address, WR strobe and data output to RCE asserted Description 20 - - tH(RCE) Hold time of address, WR strobe and data output to RCE deasserted 10 - - tRCE RCE low period (with 16/32 MHz SCK) 85 - - tS(D-CE) Setup time of read data to RCE deasserted 10 - - tACC RAM access time Tce -Ts (d-rce) 75 - - tH(RCE-D) Hold time of read data to RCE deasserted 0 - - tH(CYC) Hold time before data bus driven low 50 - 70 Unit ns 1. RCK at 16 MHz. RA[], RWRN TH(CYC) TS(RCE) TRCE TB(RCE) RCEHN, RCELN TS(D-RCE) TH(RCE-D) RD[], READ RD[], WRITE Figure 6. Shared Memory Timing The shared memory cycle time is 2 RCK clock periods. When the memory interface is not active the data bus RD[15:0] is output (low). This ensures the shared memory data bus does not float and consume power. 16 Oki Semiconductor –––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––– ■ MSM7712 ■ E2PROM Interface E2PROM Timing [1] Parameter Description Min. Typ. Max. tSKL Clock low time - 2000 - tSKH Clock high time - 2000 - tSU CS,DI setup time to rising clock - 2000-125 - tS(DO-SK) Setup time of read data to rising clock 10 - - tH(SK-DO) Hold time of read data to rising clock 0 - - Symbol ns 1. RCK at 16 MHz. EECS tSKI tSKH EESK tSU EEDI tS(DO-SK) tH(SK-DO) EEDO Figure 7. E2PROM Timing Radio Control Timing The following diagram shows a typical receive-transmit-receive sequence. RXPHE is asserted for receive. When CSENSE is detected(1) a packet is received. When CSENSE is inactive a transmit is requested by TXPHYE asserted. Delays between the receive control pins RXCx and transmit control pins TXCx are programmable to suit different radio designs. The packet is transmitted and when no further information is to be transmitted TXPHYE is deasserted. The modem holds CSENSE (2) until the ramp down is complete when the transmit control pins are deasserted and receive control pins are asserted. Note: RXPHYE, TXPHYE and CSENSE are internal signals. Radio Control Timing [1] Min. Typ. Max. tONRT1 Parameter RXC1 deasserted to TXC1 asserted Description 0 3000 7000 tONTIT2 TXC1 asserted to TXC2 asserted 0 2000 7000 tONT1IF TXC2 asserted to IF data output 0 2000 15000 tOFFCST2 CSENSE deasserted to TXC2 deasserted 0 5 20 tOFFT2T1 TXC2 deasserted to TXC1 deasserted 0 4000 7000 tOFFT1R TXC1 deasserted to RXC1 asserted 0 1000 7000 Oki Semiconductor Symbol ns 17 ■ MSM7712 ■ ––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––– 1. RCK at 16 MHz RXPHYE TXPHYE (1) (2) CSENSE RXC1 tONRT1 tOFFT1R TXC1 tONT1T2 tOFFCST2 tOFFT2T1 TXC2 tONT1IF IFD[] Rx-IF Rx-IF with Ramp Up/Down Figure 8. Radio Control Timing Synthesizer and DAC Programming Synthesizer Programming Timing [1] Min. Typ. Max. tCKL Parameter Clock low time, 8 MHz Description 60 62.5 65 tCKH Clock high time, 8 MHz 60 62.5 65 tD(DAT-CK) Delay time of data from falling clock 10 - - tS(DAT-CK) Setup time of data before rising edge - - TCKL-TD(DAT-CK) tD(CK-LE) Delay time of latch enable from clock - - TCKL-TD(DAT-CK) 1. RCK at 16 MHz. SYNLEN, DACEN tCKH tCKL tD(CK-LE) SYNCLK tD(DAT-CK) tS(DAT-CK) SYNDAT D[23] D[22] D[21] D[1] D[0] Figure 9. Synthesizer Programming Timing and DAC Timing 18 Oki Semiconductor Symbol ns –––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––– ■ MSM7712 ■ Modem Interface IFD[5:0] Bus Timing (MSEL=1..3, Transmitting) Parameter Td (ifd-rk) Description Delay time of IFD[] data from rising SCK Min. Typ. Max. 10 – – Symbol ns RCK tD(IFD-RK) IFD[5:0] Figure 10. IFD[5:0] Bus Timing (MSEL = 1…3, Transmitting) IFD[3:0] Bus Timing (MSEL=2, Receiving) Min. Typ. Max. Ts (rk-ifd) Symbol 10 - - Setup time of IFD[] data to rising clock Notes (RCK at 16 MHz) Th (ifd-rk) 0 - - Hold time of IFD[] data after rising clock RCK tS(RK-IFD) tS(IFD-RK) IFD[3:0] Figure 11. IFD[3:0] Bus Timing (MSEL = 2, Receiving) Oki Semiconductor 19 ■ MSM7712 ■ ––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––– SCK, RCK, PCLK Timing SCK, RCK, PCLK Timing Symbol Min. Typ. Max. Tskl 12.5 16.625 - Tskh 12.5 16.625 - 0 10 20 Td (prck-sck) Notes (RCK at 16 MHz System Clock low time System Clock high time Delay time from SCK rising edge to PCLK and SCK changing state tSKI tSKH SCK tD(PRCK-SCK) RCK, PCK (1) tD(PRCK-SCK) PCLK (2) Note: PCLK (1) when PCLK_DIV = 2, 4, or 8. PCLK (2) when PCLK_DIV = 1. Figure 12. SCK, RCK, PCK Timing 20 Oki Semiconductor