The binary ts7553_opencore_xuarts.vme.gz is an alternative bitstream
that substitutes the CAN bus with 4 additional XUARTs which are brought
out on the 26-Pin header as such:

PIN#    FUNCTION
19	DIO19, XUART4 Tx
20	DIO20, XUART4 Rx
21	DIO21, XUART5 Tx
22	DIO22, XUART5 Rx
23	DIO23, XUART6 Tx
24      DIO24, XUART6 Rx
25      DIO25, XUART7 Tx
26      DIO26, XUART7 Rx

The binary differs from the source in that the source reflects what
ships with the factory TS-7553 FPGA load (ie. No XUARTs, 1 CAN Bus).
The parameters to match the binary configuration are available in
the source (see below).

FACTORY ts7553_top.v:
parameter sdcard_opt = 1'b1;
parameter spi_opt = 1'b1;
parameter nandflash_opt = 1'b1;
parameter can_opt = 1'b1;
/* software currently requires these to be enabled/disabled contiguously. */
parameter xuart0_opt = 1'b1;
parameter xuart1_opt = 1'b1;
parameter xuart2_opt = 1'b1;
parameter xuart3_opt = 1'b1;
parameter xuart4_opt = 1'b0;
parameter xuart5_opt = 1'b0;
parameter xuart6_opt = 1'b0;
parameter xuart7_opt = 1'b0;

ALTERNATIVE ts7553_top.v:
parameter sdcard_opt = 1'b1;
parameter spi_opt = 1'b1;
parameter nandflash_opt = 1'b1;
parameter can_opt = 1'b0;
/* software currently requires these to be enabled/disabled contiguously. */
parameter xuart0_opt = 1'b1;
parameter xuart1_opt = 1'b1;
parameter xuart2_opt = 1'b1;
parameter xuart3_opt = 1'b1;
parameter xuart4_opt = 1'b1;
parameter xuart5_opt = 1'b1;
parameter xuart6_opt = 1'b1;
parameter xuart7_opt = 1'b1;
