DLPU125 june 2023
The USB GPIF port provides access to Apps FPGA internal control-status registers. The USB GPIF port also provides a data input FIFO used for loading the user image buffer with user images for display. Table 3-6 describes the signals in the interface.
Name | Apps FPGA I/O | Function |
---|---|---|
gpif_addr(8:0) |
in | Not used |
usb_fd(15:0) |
in/out | USB GPIF data, bi-directional |
usb_ctrl(5:3) |
in | USB GPIF control – not used(1) |
usb_ctrl(2:0) |
in | USB GPIF control, identifies transaction type |
usb_rdy(2:1) |
out | USB GPIF ready outputs – not used(2) |
usb_rdy(0) |
out | USB GPIF ready output 0(3) |
usb_reset |
out | Not used – apps FPGA drives low always |
usb_if_clock |
in | USB GPIF clock, 48 MHz |
usb_ctrl(5:3)
inputs are not used.usb_rdy(2:1)
outputs are always driven low.usb_rdy(0)
is
the empty flag of the USB GPIF input FIFO.The type of GPIF transaction is
defined by usb_ctrl(2:0)
as shown in Table 3-7.
Signal | Idle | Address | Data write | Data read | FIFO burst |
---|---|---|---|---|---|
usb_ctrl(2) |
1 | 0 | 0 | 0 | 1 |
usb_ctrl(1) |
1 | 1 | 1 | 0 | 1 |
usb_ctrl(0) |
1 | 1 | 0 | 1 | 0 |