1 //-----------------------------------------------------------------------------
2 // The FPGA is responsible for interfacing between the A/D, the coil drivers,
3 // and the ARM. In the low-frequency modes it passes the data straight
4 // through, so that the ARM gets raw A/D samples over the SSP. In the high-
5 // frequency modes, the FPGA might perform some demodulation first, to
6 // reduce the amount of data that we must send to the ARM.
8 // I am not really an FPGA/ASIC designer, so I am sure that a lot of this
11 // Jonathan Westhues, March 2006
12 // Added ISO14443-A support by Gerhard de Koning Gans, April 2008
13 //-----------------------------------------------------------------------------
16 `include "lo_passthru.v"
17 `include "lo_simulate.v"
18 `include "hi_read_tx.v"
19 `include "hi_read_rx_xcorr.v"
20 `include "hi_simulate.v"
21 `include "hi_iso14443a.v"
25 spcki, miso, mosi, ncs,
26 pck0i, ck_1356meg, ck_1356megb,
27 pwr_lo, pwr_hi, pwr_oe1, pwr_oe2, pwr_oe3, pwr_oe4,
28 adc_d, adc_clk, adc_noe,
29 ssp_frame, ssp_din, ssp_dout, ssp_clk,
33 input spcki, mosi, ncs;
35 input pck0i, ck_1356meg, ck_1356megb;
36 output pwr_lo, pwr_hi, pwr_oe1, pwr_oe2, pwr_oe3, pwr_oe4;
38 output adc_clk, adc_noe;
40 output ssp_frame, ssp_din, ssp_clk;
41 input cross_hi, cross_lo;
44 //assign pck0 = pck0i;
45 IBUFG #(.IOSTANDARD("DEFAULT") ) pck0b(
49 //assign spck = spcki;
50 IBUFG #(.IOSTANDARD("DEFAULT") ) spckb(
54 //-----------------------------------------------------------------------------
55 // The SPI receiver. This sets up the configuration word, which the rest of
56 // the logic looks at to determine how to connect the A/D and the coil
57 // drivers (i.e., which section gets it). Also assign some symbolic names
58 // to the configuration bits, for use below.
59 //-----------------------------------------------------------------------------
65 // We switch modes between transmitting to the 13.56 MHz tag and receiving
66 // from it, which means that we must make sure that we can do so without
67 // glitching, or else we will glitch the transmitted carrier.
70 case(shift_reg[15:12])
71 4'b0001: conf_word <= shift_reg[7:0];
72 4'b0010: divisor <= shift_reg[7:0];
76 always @(posedge spck)
80 shift_reg[15:1] <= shift_reg[14:0];
85 wire [2:0] major_mode;
86 assign major_mode = conf_word[7:5];
88 // For the low-frequency configuration:
90 assign lo_is_125khz = conf_word[3];
92 // For the high-frequency transmit configuration: modulation depth, either
93 // 100% (just quite driving antenna, steady LOW), or shallower (tri-state
94 // some fraction of the buffers)
95 wire hi_read_tx_shallow_modulation;
96 assign hi_read_tx_shallow_modulation = conf_word[0];
98 // For the high-frequency receive correlator: frequency against which to
100 wire hi_read_rx_xcorr_848;
101 assign hi_read_rx_xcorr_848 = conf_word[0];
102 // and whether to drive the coil (reader) or just short it (snooper)
103 wire hi_read_rx_xcorr_snoop;
104 assign hi_read_rx_xcorr_snoop = conf_word[1];
106 // Divide the expected subcarrier frequency for hi_read_rx_xcorr by 4
107 wire hi_read_rx_xcorr_quarter;
108 assign hi_read_rx_xcorr_quarter = conf_word[2];
110 // For the high-frequency simulated tag: what kind of modulation to use.
111 wire [2:0] hi_simulate_mod_type;
112 assign hi_simulate_mod_type = conf_word[2:0];
114 //-----------------------------------------------------------------------------
115 // And then we instantiate the modules corresponding to each of the FPGA's
116 // major modes, and use muxes to connect the outputs of the active mode to
118 //-----------------------------------------------------------------------------
121 pck0, ck_1356meg, ck_1356megb,
122 lr_pwr_lo, lr_pwr_hi, lr_pwr_oe1, lr_pwr_oe2, lr_pwr_oe3, lr_pwr_oe4,
124 lr_ssp_frame, lr_ssp_din, ssp_dout, lr_ssp_clk,
127 lo_is_125khz, divisor
131 pck0, ck_1356meg, ck_1356megb,
132 lp_pwr_lo, lp_pwr_hi, lp_pwr_oe1, lp_pwr_oe2, lp_pwr_oe3, lp_pwr_oe4,
134 lp_ssp_frame, lp_ssp_din, ssp_dout, lp_ssp_clk,
140 pck0, ck_1356meg, ck_1356megb,
141 ls_pwr_lo, ls_pwr_hi, ls_pwr_oe1, ls_pwr_oe2, ls_pwr_oe3, ls_pwr_oe4,
143 ls_ssp_frame, ls_ssp_din, ssp_dout, ls_ssp_clk,
149 pck0, ck_1356meg, ck_1356megb,
150 ht_pwr_lo, ht_pwr_hi, ht_pwr_oe1, ht_pwr_oe2, ht_pwr_oe3, ht_pwr_oe4,
152 ht_ssp_frame, ht_ssp_din, ssp_dout, ht_ssp_clk,
155 hi_read_tx_shallow_modulation
158 hi_read_rx_xcorr hrxc(
159 pck0, ck_1356meg, ck_1356megb,
160 hrxc_pwr_lo, hrxc_pwr_hi, hrxc_pwr_oe1, hrxc_pwr_oe2, hrxc_pwr_oe3, hrxc_pwr_oe4,
162 hrxc_ssp_frame, hrxc_ssp_din, ssp_dout, hrxc_ssp_clk,
165 hi_read_rx_xcorr_848, hi_read_rx_xcorr_snoop, hi_read_rx_xcorr_quarter
169 pck0, ck_1356meg, ck_1356megb,
170 hs_pwr_lo, hs_pwr_hi, hs_pwr_oe1, hs_pwr_oe2, hs_pwr_oe3, hs_pwr_oe4,
172 hs_ssp_frame, hs_ssp_din, ssp_dout, hs_ssp_clk,
179 pck0, ck_1356meg, ck_1356megb,
180 hisn_pwr_lo, hisn_pwr_hi, hisn_pwr_oe1, hisn_pwr_oe2, hisn_pwr_oe3, hisn_pwr_oe4,
182 hisn_ssp_frame, hisn_ssp_din, ssp_dout, hisn_ssp_clk,
189 // 000 -- LF reader (generic)
190 // 001 -- LF simulated tag (generic)
191 // 010 -- HF reader, transmitting to tag; modulation depth selectable
192 // 011 -- HF reader, receiving from tag, correlating as it goes; frequency selectable
193 // 100 -- HF simulated tag
194 // 101 -- HF ISO14443-A
195 // 110 -- LF passthrough
196 // 111 -- everything off
198 mux8 mux_ssp_clk (major_mode, ssp_clk, lr_ssp_clk, ls_ssp_clk, ht_ssp_clk, hrxc_ssp_clk, hs_ssp_clk, hisn_ssp_clk, lp_ssp_clk, 1'b0);
199 mux8 mux_ssp_din (major_mode, ssp_din, lr_ssp_din, ls_ssp_din, ht_ssp_din, hrxc_ssp_din, hs_ssp_din, hisn_ssp_din, lp_ssp_din, 1'b0);
200 mux8 mux_ssp_frame (major_mode, ssp_frame, lr_ssp_frame, ls_ssp_frame, ht_ssp_frame, hrxc_ssp_frame, hs_ssp_frame, hisn_ssp_frame, lp_ssp_frame, 1'b0);
201 mux8 mux_pwr_oe1 (major_mode, pwr_oe1, lr_pwr_oe1, ls_pwr_oe1, ht_pwr_oe1, hrxc_pwr_oe1, hs_pwr_oe1, hisn_pwr_oe1, lp_pwr_oe1, 1'b0);
202 mux8 mux_pwr_oe2 (major_mode, pwr_oe2, lr_pwr_oe2, ls_pwr_oe2, ht_pwr_oe2, hrxc_pwr_oe2, hs_pwr_oe2, hisn_pwr_oe2, lp_pwr_oe2, 1'b0);
203 mux8 mux_pwr_oe3 (major_mode, pwr_oe3, lr_pwr_oe3, ls_pwr_oe3, ht_pwr_oe3, hrxc_pwr_oe3, hs_pwr_oe3, hisn_pwr_oe3, lp_pwr_oe3, 1'b0);
204 mux8 mux_pwr_oe4 (major_mode, pwr_oe4, lr_pwr_oe4, ls_pwr_oe4, ht_pwr_oe4, hrxc_pwr_oe4, hs_pwr_oe4, hisn_pwr_oe4, lp_pwr_oe4, 1'b0);
205 mux8 mux_pwr_lo (major_mode, pwr_lo, lr_pwr_lo, ls_pwr_lo, ht_pwr_lo, hrxc_pwr_lo, hs_pwr_lo, hisn_pwr_lo, lp_pwr_lo, 1'b0);
206 mux8 mux_pwr_hi (major_mode, pwr_hi, lr_pwr_hi, ls_pwr_hi, ht_pwr_hi, hrxc_pwr_hi, hs_pwr_hi, hisn_pwr_hi, lp_pwr_hi, 1'b0);
207 mux8 mux_adc_clk (major_mode, adc_clk, lr_adc_clk, ls_adc_clk, ht_adc_clk, hrxc_adc_clk, hs_adc_clk, hisn_adc_clk, lp_adc_clk, 1'b0);
208 mux8 mux_dbg (major_mode, dbg, lr_dbg, ls_dbg, ht_dbg, hrxc_dbg, hs_dbg, hisn_dbg, lp_dbg, 1'b0);
210 // In all modes, let the ADC's outputs be enabled.
211 assign adc_noe = 1'b0;