OCRP RF Control WINLAB – Rutgers University Date : June Authors : Prasanthi Maddala, Khanh Le,

SPI – Serial Peripheral Interface Synchronous serial data link standard. Operates in master/slave mode. SPI specifies 4 logic signals SCLK — Serial Clock (output from master) MOSI/SIMO — Master Output, Slave Input (output from master) MISO/SOMI — Master Input, Slave Output (output from slave) SS — Slave Select (active low; output from master) Some SPI slave devices do not have a data output port (No MISO) and a few devices use a bidirectional data port (MOSI/MISO). Data Transmission - Master configures the clock; uses a frequency < max. freq supported by the slave - Pulls the slave select low - During each clock cycle the Master sends a bit on MOSI and slave sends a bit on MISO – not all transmissions result in meaningful rd/wr s. Clock polarity and phase - In addition to setting the clock frequency, the master must also configure the clock polarity(cpol) and phase(cpha) with respect to the data.

SPI (contd.) At CPOL=0 base value of the clock is zero  For CPHA=0 (first edge), data is read on the clock's rising edge and data is changed on a falling edge  For CPHA=1 (second edge), data is read on the clock's falling edge and data is changed on a rising edge. At CPOL=1 the base value of the clock is one (inversion of CPOL=0)  For CPHA=0, data is read on clock's falling edge and data is changed on a rising edge.  For CPHA=1, data is read on clock's rising edge and data is changed on a falling edge. This timing applies to both the master and the slave device.

RF Control OCRP RF Control block supports up to 4 RF modules (SDR/ SDR with FreeBo/ WDR/XDR(?)) Generics: RF_BOARD – SDR/SDRwithFreeBo/WDR/XDR NO_OF_RF_CARDS - 1 or 2 for SDR, 1 for SDR with FreeBo, 1-4 for WDR, 1-4 for XDR SPI_PER_CARD_SHARED – TRUE or FALSE for SDR, SDRwith FreeBo, always TRUE for WDR, XDR RF Inf shown above (o_board_out[6:0], i_board_in) is compatible with SDR and WDR – might have to add additional lines to support SDR with Freebo, XDR

RF Control – RMAP Interface Signal NameIn/OutWidthDescription i_rfctl_wr_dataIn40Data to be sent to the SPI device serially – MSB first i_spi_cycle_lenIn6Length of the SPI communication cycle - Ex: length of valid write data for an SPI wr cycle. i_selIn4SPI device code i_enIn1Rising edge on this signal indicates a request for start of SPI transmission i_modeIn2SPI mode – cpol&cpha i_freq_divIn4Freq. of sclk = Freq. of i_clk / (2 ^ i_freq_div) i_stall_startIn6No.of sclk cycles after which sclk has to be stalled. 0 – no clock stalling i_stall_stopIn6No.of sclk cycles after which sclk comes out of stall mode and runs normally. o_rfctl_rd_dataOut32Data read from the SPI device during an SPI communication cycle. o_doneOut1Rising edge on this signal indicates the completion of an SPI communication cycle.

SDR Platform V1.1 (Dual RF)

SPI Devices on SDR V1.1 DeviceNo. on WDR Comm. Cycle width Type of SPI AD9862 (ADC/DAC on DiBo) 216 or 244-wire. Allows 2 word write. MSB(dflt) or LSB first. Max sclk- 16 MHz. Data read on rising edge, clocked out on falling edge. MAX2829 (RF Transceiver on WiBo) 2183-wire, MSB first. No read. Max sclk-40 MHz(?). Data read on rising edge. MM74HC595 (U2- RF Control Register on WiBo) 28Can be thought of as a 3-wire SPI device with sclk connected to the shift register clock and cs connected to the storage register clock. Data read on rising edge. Antenna Switches are controlled from the common RMAP directly just like the LEDs – they don’t go through the RF control block

RF Control for SDR (1 SPI per RF)

Generic SPI Generics MAX_SPI_CYCLE_LEN (40 for OCRP) MAX_SPI_CYCLE_LEN_BITS (6 for OCRP) NO_OF_SLAVE_SEL_INPUT_BITS (4 for OCRP) SLAVE_SEL_ENCODED (depends on RF) NO_OF_SLAVE_SEL_OUTPUTS (depends on RF) DELAY_TO_SLAVE (depends on RF) - 0 if the SPI master core is directly connected to the slave. If its output is being processed before connecting to the slave, specify the delay involved in terms of sclk cycles. For SDR (1 SPI per RF) SLAVE_SEL_ENCODED - FALSE NO_OF_SLAVE_SEL_OUTPUTS - 1 DELAY_TO_SLAVE – 1 (since SDR RF inf involves a delay of 1 sclk cycle)

Generic SPI output Signal NameIn/OutWidthDescription o_sclkOut1Serial clock to the slave o_sdiOut1Serial data out i_sdoIn1Serial data in o_csOutNO_OF_SLAVE_S EL_OUTPUTS Chip selects for slaves – this bus gives individual chip select lines or encoded chip select depending on the SLAVE_SEL_ENCODED generic. Ex: NO_OF_SLAVE_SEL_OUTPUTS = 4 SLAVE_SEL_ENCODED = TRUE - the master can select up to 15 slave devices (with one idle ?) o_sclk_x2Out1This is a clock output with freq. double that of sclk. It can be used by a block between the master and the slaves. Ex: DELAY_TO_SLAVE = 1, the intermediate block consists of 2 reg. stages which use o_sclk_x2 o_selOutNO_OF_SLAVE_S EL_INPUT_BITS SPI master can give multiple chip select lines directly to the slaves or give a single chip select that is further passed through a demux to select among various slaves. o_sel can be used by such a demux. (o_sel = i_sel)

AD registers, 8 bit wide. Max sclk freq = 16 MHz 16/24 bit rd/wr cycle - registers are updated on 16 th or 24 th rising clock edge. Incomplete operations are ignored Writing to a register rmap_cmd(wr, spi_wr_reg_0, 00(rd/wr & 2/1)&addr(6 bits)&data(8 bits)) -- data(16) for 2 word write rmap_cmd(wr, spi_ctl_reg, x”0000” & b”00&010000(cycle_length-16)&0010(AD9862)&000&1) rmap_cmd(wr, spi_ctl_reg, x”0000” & b”00&010000(cycle_length-16)&0010(AD9862)&000&0) Reading from a register rmap_cmd(wr, spi_wr_reg_0, 10&addr(6)&dummydata(8)) -- data(16) for 2 word rd rmap_cmd(wr, spi_ctl_reg, x”0000” & b”00&010000(cycle_length-16)&0010(AD9862)&000&1) rmap_cmd(wr, spi_ctl_reg, x”0000” & b”00&010000(cycle_length-16)&0010(AD9862)&000&0) rmap_cmd(rd, spi_rd_reg) - spi_rd_reg(7:0) will contain the required data SPI Config register stall_start – stall_stop – mode -00 freq_div – 0011 (gives 12.5MHz sclk when i_clk = 100 MHz)

MAX registers, 14 bit wide. 18 bit wr cycle – less than 18 bits are allowed. Frame starts with nCS going low and ends with nCS going high. Last 18 bits that are shifted in are latched with the rising edge of nCS. Bits are shifted in MSB first, on rising edge of sclk when nCS is low. Writing to a register rmap_cmd(wr, spi_wr_reg_0, data(14)&addr(4)) rmap_cmd(wr, spi_ctl_reg, x”0000” & b”00&010010(cycle_length-18)&0000(MAX2829)&000&1) rmap_cmd(wr, spi_ctl_reg, x”0000” & b”00&010010(cycle_length-18)&0000(MAX2829)&000&0) SPI Config register stall_start – stall_stop – mode -00 freq_div – 0011 (gives 12.5MHz sclk when i_clk = 100 MHz)

MM74HC595

WDR RF Control

Signal NameIn/OutWidthDescription i_start_txIn1Rising edge on this signal is a request for start of transmission (an SPI communication cycle) i_wr_dataInMAX_CYCLE_WIDTH (RF Control Generic ) Data to be clocked out serially (MSB first) i_cycle_lenIn6Length of the communication cycle – size of rd/wr data i_stall_startIn6No.of sclk cycles after which sclk has to be stalled. 0 – no clock stalling i_stall_stopIn6No.of sclk cycles after which sclk comes out of stall mode and runs normally. i_freq_divIn4Freq. of sclk = Freq. of i_clk / (2 ^ i_freq_div) i_modeIn2Spi mode – cpol&cpha o_rd_dataOutMAX_CYCLE_WIDTH (RF Control Generic ) Data read from the SPI device during a communication cycle o_tx_doneOut1Rising edge on this signal indicates the end of a communication cycle, acts a sync pulse for o_rd_data. Generic SPI – SPI Control Interface –old slide