The TSW1405EVM Low Cost Data Capture Card from Texas Instruments (TI) assists designers in prototyping and
evaluating the performance of high-speed ADCs that feature parallel/serial LVDS outputs. The evaluation module
features a powerful LatticeECP3™-35 FPGA. The FPGA can be used as a flexible and rapid prototyping environment for digital design, interfacing directly to the LVDS output of the TI ADC under evaluation. This HDL reference
design is available for users to get started with the evaluation board and capture ADC data using the TI High Speed
Data Converter Pro software.
Figure 1. Hardware Evaluation Overview
High Speed Data Converter Pro
Currently, HDL reference designs targeting the LatticeECP3 device support the following TI device families:
• ADS41xx and ADS61xx single channel
• ADS62Pxx and ADS42xx dual channel
• ADS58C48 four channel
• ADS5400 dual bus
• ADS5463 single channel
• ADS5485 single channel
The HDL reference designs for these converters contain two primary modules for capturing the LVDS data from the
ADC.
• ADCIF – Contains the I/O logic and gearing functions for the LVDS pins. It also converts the double data rate
(DDR) input channel to a single data rate (SDR) parallel bus.
• DUMPMEM_TOP – Stores the channel’s parallel data to internal DPRAM. The ADC data extracts a SPI controller within the module. The High Speed Data Converter Pro software can import the data from this controller
through the USB port.
ADCIF module is the only design block required if the user desires to implement their own design using the
ADS41xx/ADS61xx, ADS62Pxx/ADS42xx, ADS58C48, ADS5400, ADS5463, ADS5485 with the LatticeECP3
device. The top level design instantiates the primary modules and connects them together. It also contains a LED
blinker circuit. This circuit flashes the LED when the LVDS clock output from the ADC is running and is available to
the FPGA. Figures 2 to 7 show the block diagrams for each respective ADC design.
Figure 6. Single Channel ADC Block Diagram (ADS5463)
HDL User’s Guide
Figure 7. Single Channel ADC Block Diagram (ADS5485)
The input of the ADCIF module is the single or dual channel double data rate (DDR) output from the ADC. This
input is converted to two single data rate buses for each channel at half the rate of the ADC input clock. The single
channel design is capable of handling up to eight LVDS DDR inputs from the ADC. The dual channel design is
capable of handling up to seven LVDS DDR inputs for the ADC. Table 2 describes the ADCIF I/O for single and dual
channel designs.
Table 4. Single Channel Design Signal Names and Pinout
Signal NameLatticeECP3 PinDirectionDefinition
reset_nC21InputMaster Reset
clk_lvds_rx_pL4
clk_lvds_rx_nM4
lvds_rx_port0_p[4]AA1
lvds_rx_port0_n[4]Y2
lvds_rx_port0_p[5]T4
lvds_rx_port0_n[5]T5
lvds_rx_port0_p[6]U1
lvds_rx_port0_n[6]U2
lvds_rx_port0_p[7]N3
lvds_rx_port0_n[7]P3
lvds_rx_port0_p[9]L3
lvds_rx_port0_n[9]L2
lvds_rx_port0_p[10]N4
lvds_rx_port0_n[10]P4
lvds_rx_port0_p[11]N5
lvds_rx_port0_n[11]P6
lvds_rx_port0_p[12]R7
lvds_rx_port0_n[12]T7
clk_spiA20InputSPI Clock
spi_misoB19OutputSPI Data Out
spi_ssB20InputSPI Source Select
LEDF19OutputADC Clock Active Status
regbitG18OutputReserved
HDL User’s Guide
InputClock from TI ADC
InputTI ADC Channel 1 Data
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TI TSW1405 High-Speed ADC Evaluation Board
Table 5. Dual Channel Design Signal Names and Pinout
Signal NameLatticeECP3 PinDirectionDefinition
reset_nC21InputMaster Reset
clk_lvds_rx_pL4InputClock from TI ADC
clk_lvds_rx_nM4
lvds_rx_port0_p[1]R4
lvds_rx_port0_n[1]T5
lvds_rx_port0_p[2]R3
lvds_rx_port0_n[2]R2
lvds_rx_port0_p[3]B2
lvds_rx_port0_n[3]C2
lvds_rx_port0_p[4]AA1
lvds_rx_port0_n[4]Y2
lvds_rx_port0_p[5]T4
lvds_rx_port0_n[5]T5
lvds_rx_port0_p[6]U1
lvds_rx_port0_n[6]U2
lvds_rx_port0_p[7]N3
lvds_rx_port0_n[7]P3
lvds_rx_port0_p[9]L3
lvds_rx_port0_n[9]L2
lvds_rx_port0_p[10]N4
lvds_rx_port0_n[10]P4
lvds_rx_port0_p[11]N5
lvds_rx_port0_n[11]P6
lvds_rx_port0_p[12]R7
lvds_rx_port0_n[12]T7
lvds_rx_port0_p[13]E5
lvds_rx_port0_n[13]E4
lvds_rx_port0_p[14]P1
lvds_rx_port0_n[14]R1
lvds_rx_port0_p[15]M2
lvds_rx_port0_n[15]M1
clk_spiA20InputSPI Clock
spi_misoB19OutputSPI Data Out
spi_ssB20InputSPI Source Select
LEDF19OutputADC Clock Active Status
regbitG18OutputReserved
HDL User’s Guide
InputTI ADC Channel 1 Data
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TI TSW1405 High-Speed ADC Evaluation Board
HDL User’s Guide
Table 6. Four Channel Design Signal Names and Pinout
Signal NameLatticeECP3 PinDirectionDefinition
reset_nC21InputMaster Reset
clk_lvds_rx_pL4InputClock from TI ADC
clk_lvds_rx_nM4
lvds_rx_port0_p[2]R3
lvds_rx_port0_n[2]R2
lvds_rx_port0_p[3]B2
lvds_rx_port0_n[3]C2
lvds_rx_port0_p[4]AA1
lvds_rx_port0_n[4]Y2
lvds_rx_port0_p[5]T4
lvds_rx_port0_n[5]U4
lvds_rx_port0_p[6]U1
lvds_rx_port0_n[6]U2
lvds_rx_port0_p[7]N3
lvds_rx_port0_n[7]P3
lvds_rx_port0_p[10]N4
lvds_rx_port0_n[10]P4
lvds_rx_port0_p[11]N5
lvds_rx_port0_n[11]P6
lvds_rx_port0_p[12]R7
lvds_rx_port0_n[12]T7
lvds_rx_port0_p[13]E5
lvds_rx_port0_n[13]E4
lvds_rx_port0_p[14]P1
lvds_rx_port0_n[14]R1
lvds_rx_port0_p[15]M2
lvds_rx_port0_n[15]M1
lvds_rx_port1_p[0]V4
lvds_rx_port1_n[0]V5
lvds_rx_port1_p[1]V3
lvds_rx_port1_n[1]W3
lvds_rx_port1_p[2]Y3
lvds_rx_port1_n[2]AA2
lvds_rx_port1_p[3]W2
lvds_rx_port1_n[3]Y1
lvds_rx_port1_p[4]V1
lvds_rx_port1_n[4]W1
lvds_rx_port1_p[5]K4
lvds_rx_port1_n[5]K5
lvds_rx_port1_p[6]G3
lvds_rx_port1_n[6]G2
lvds_rx_port1_p[7]J2
lvds_rx_port1_n[7]J1
lvds_rx_port1_p[8]G1
InputTI ADC Channel 1 Data
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TI TSW1405 High-Speed ADC Evaluation Board
HDL User’s Guide
Table 6. Four Channel Design Signal Names and Pinout (Continued)
Signal NameLatticeECP3 PinDirectionDefinition
lvds_rx_port1_n[8]H1
lvds_rx_port1_p[9]E1
lvds_rx_port1_n[9]F1
lvds_rx_port1_p[10]D2
lvds_rx_port1_n[10]D1
lvds_rx_port1_p[11]B1
lvds_rx_port1_n[11]C1
clk_spiA20InputSPI Clock
spi_misoB19OutputSPI Data Out
spi_ssB20InputSPI Source Select
LEDF19OutputADC Clock Active Status
regbitG18OutputReserved
Input
Table 7. Dual Bus Design Signal Names and Pinout
Signal NameLatticeECP3 PinDirectionDefinition
reset_nC21InputMaster Reset
clk_lvds_rx_pL4InputClock from TI ADC
clk_lvds_rx_nM4
lvds_rx_port0_p[3]B2
lvds_rx_port0_n[3]C2
lvds_rx_port0_p[4]AA1
lvds_rx_port0_n[4]Y2
lvds_rx_port0_p[5]T4
lvds_rx_port0_n[5]U4
lvds_rx_port0_p[6]U1
lvds_rx_port0_n[6]U2
lvds_rx_port0_p[7]N3
lvds_rx_port0_n[7]P3
lvds_rx_port0_p[10]N4
lvds_rx_port0_n[10]P4
lvds_rx_port0_p[11]N5
lvds_rx_port0_n[11]P6
lvds_rx_port0_p[12]R7
lvds_rx_port0_n[12]T7
lvds_rx_port0_p[13]E5
lvds_rx_port0_n[13]E4
lvds_rx_port0_p[14]P1
lvds_rx_port0_n[14]R1
lvds_rx_port1_p[0]V4
lvds_rx_port1_n[0]V5
lvds_rx_port1_p[1]V3
lvds_rx_port1_n[1]W3
lvds_rx_port1_p[2]Y3
lvds_rx_port1_n[2]AA2
InputTI ADC Channel 1 Data
TI ADC Channel 1 Data
(cont.)
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TI TSW1405 High-Speed ADC Evaluation Board
HDL User’s Guide
Table 7. Dual Bus Design Signal Names and Pinout (Continued)
Signal NameLatticeECP3 PinDirectionDefinition
lvds_rx_port1_p[3]W2
lvds_rx_port1_n[3]Y1
lvds_rx_port1_p[4]V1
lvds_rx_port1_n[4]W1
lvds_rx_port1_p[5]K4
lvds_rx_port1_n[5]K5
lvds_rx_port1_p[6]G3
lvds_rx_port1_n[6]G2
lvds_rx_port1_p[7]J2
lvds_rx_port1_n[7]J1
lvds_rx_port1_p[8]G1
lvds_rx_port1_n[8]H1
lvds_rx_port1_p[9]E1
lvds_rx_port1_n[9]F1
lvds_rx_port1_p[10]D2
lvds_rx_port1_n[10]D1
lvds_rx_port1_p[11]B1
lvds_rx_port1_n[11]C1
clk_spiA20InputSPI Clock
spi_misoB19OutputSPI Data Out
spi_ssB20InputSPI Source Select
LEDF19OutputADC Clock Active Status
regbitG18OutputReserved
Input
TI ADC Channel 1 Data
(cont.)
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TI TSW1405 High-Speed ADC Evaluation Board
HDL User’s Guide
Table 8. Sample-Wise Design Signal Names and Pinout
Signal NameLatticeECP3 PinDirectionDefinition
reset_nC21InputMaster Reset
clk_lvds_rx_pL4InputClock from TI ADC
clk_lvds_rx_nM4
lvds_rx_port0_p[1]R4
lvds_rx_port0_n[1]T5
lvds_rx_port0_p[2]R3
lvds_rx_port0_n[2]R2
lvds_rx_port0_p[3]B2
lvds_rx_port0_n[3]C2
lvds_rx_port0_p[4]AA1
lvds_rx_port0_n[4]Y2
lvds_rx_port0_p[5]T4
lvds_rx_port0_n[5]T5
lvds_rx_port0_p[6]U1
lvds_rx_port0_n[6]U2
lvds_rx_port0_p[7]N3
lvds_rx_port0_n[7]P3
lvds_rx_port0_p[9]L3
lvds_rx_port0_n[9]L2
lvds_rx_port0_p[10]N4
lvds_rx_port0_n[10]P4
lvds_rx_port0_p[11]N5
lvds_rx_port0_n[11]P6
lvds_rx_port0_p[12]R7
lvds_rx_port0_n[12]T7
lvds_rx_port0_p[13]E5
lvds_rx_port0_n[13]E4
lvds_rx_port0_p[14]P1
lvds_rx_port0_n[14]R1
clk_spiA20InputSPI Clock
spi_misoB19OutputSPI Data Out
spi_ssB20InputSPI Source Select
LEDF19OutputADC Clock Active Status
regbitG18OutputReserved
InputTI ADC Channel 1 Data
12
TI TSW1405 High-Speed ADC Evaluation Board
HDL User’s Guide
Table 9. Single Channel Edge Bit-Wise Design Signal Names and Pinout
Signal NameLatticeECP3 PinDirectionDefinition
reset_nC21InputMaster Reset
clk_lvds_rx_pL4InputClock from TI ADC
clk_lvds_rx_nM4
lvds_rx_port0_p[4]AA1
lvds_rx_port0_n[4]Y2
lvds_rx_port0_p[5]T4
lvds_rx_port0_n[5]T5
lvds_rx_port0_p[6]U1
lvds_rx_port0_n[6]U2
lvds_rx_port0_p[7]N3
lvds_rx_port0_n[7]P3
lvds_rx_port0_p[9]L3
lvds_rx_port0_n[9]L2
lvds_rx_port0_p[10]N4
lvds_rx_port0_n[10]P4
lvds_rx_port0_p[11]N5
lvds_rx_port0_n[11]P6
lvds_rx_port0_p[12]R7
lvds_rx_port0_n[12]T7
clk_spiA20InputSPI Clock
spi_misoB19OutputSPI Data Out
spi_ssB20InputSPI Source Select
LEDF19OutputADC Clock Active Status
regbitG18OutputReserved
InputTI ADC Channel 1 Data
Hardware Validation
Hardware was validated using the ADS61B49EVM, ADS4249, ADS58C48, ADS5400, ADS5463, ADS5485,
TSW1405, two function generators and a DC power supply. The FPGA firmware was synthesized and programed
using Lattice Diamond
Speed Data Converter Pro 1.0/1.04 GUI. The input clock frequency was set to 15 MHz at 1.5 Vpp and the ADC
input was set to 100 kHz at 4.5Vpp. The supply to the ADC board was 5V or 6V depending on the board.
®
1.4 design software. ADC results were analyzed through the Texas Instruments High-
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TI TSW1405 High-Speed ADC Evaluation Board
Figure 9. Texas Instruments High-Speed Data Converter Pro 1.0 GUI
HDL User’s Guide
References
• Texas Instruments TSW1405, High-Speed ADC LVDS Evaluation System
• Texas Instruments ADS61xx, 14/12-Bit MSPS ADCs With DDR LVDS and Parallel CMOS Outputs Data Sheet