Resource Usage

The XUD library requires the resources described in the following sections.

Ports/Pins

G/L-Series

The ports used for the physical connection to the external ULPI transceiver must be connected as shown in the table below.

ULPI required pin/port connections

Pin 1b	Port 4b			Signal 8b
Pin 1b	X0D12	P1E0			ULPI_STP
X0D13	P1F0			ULPI_NXT
X0D14		P4C0	P8B0	ULPI_DATA[7:0]
X0D15		P4C1	P8B1
X0D16		P4D0	P8B2
X0D17		P4D1	P8B3
X0D18		P4D2	P8B4
X0D19		P4D3	P8B5
X0D20		P4C2	P8B6
X0D21		P4C3	P8B7
X0D22	P1G0			ULPI_DIR
X0D23	P1H0			ULPI_CLK
X0D24	P1I0			ULPI_RST_N

In addition some ports are used internally when the XUD library is in operation. For example pins X0D2-X0D9, X0D26-X0D33 and X0D37-X0D43 on an XS1-L device should not be used.

Please refer to the device datasheet for further information on which ports are available.

U-Series

The U-Series of devices have an integrated USB transceiver. Some ports are used to communicate with the USB transceiver inside the U-Series packages. These ports/pins should not be used when USB functionality is enabled. The ports/pins are shown in the table below.

U-Series required pin/port connections

Pin 1b	Port 4b
Pin 1b	X0D02		P4A0	P8A0	P16A0	P32A20
X0D03		P4A1	P8A1	P16A1	P32A21
X0D04		P4B0	P8A2	P16A2	P32A22
X0D05		P4B1	P8A3	P16A3	P32A23
X0D06		P4B2	P8A4	P16A4	P32A24
X0D07		P4B3	P8A5	P16A5	P32A25
X0D08		P4A2	P8A6	P16A6	P32A26
X0D09		P4A3	P8A7	P16A7	P32A27
X0D23	P1H0
X0D25	P1J0
X0D26		P4E0	P8C0	P16B0
X0D27		P4E1	P8C1	P16B1
X0D28		P4F0	P8C2	P16B2
X0D29		P4F1	P8C3	P16B3
X0D30		P4F2	P8C4	P16B4
X0D31		P4F3	P8C5	P16B5
X0D32		P4E2	P8C6	P16B6
X0D33		P4E3	P8C7	P16B7
X0D34	P1K0
X0D36	P1M0		P8D0	P16B8
X0D37	P1N0		P8C1	P16B1
X0D38	P1O0		P8C2	P16B2
X0D39	P1P0		P8C3	P16B3

Core Speed

Due to I/O requirements, the library requires a guaranteed MIPS rate to ensure correct operation. This means that core count restrictions must be observed. The XUD core must run at at least 80 MIPS.

This means that for an xCORE device running at 400MHz there should be no more than five cores executing at any time when using the XUD. For a 500MHz device no more than six cores shall execute at any one time when using the XUD.

This restriction is only a requirement on the tile on which the XUD_Manager is running. For example, the other tile on an L16 device is unaffected by this restriction.

Clock Blocks

G/L-Series

The XUD library uses one clock block (clock block 0) and configures this clock block to be clocked by the 60MHz clock from the ULPI transceiver. The ports it uses are in turn clocked from the clock block.

Since clock block 0 is the default for all ports when enabled it is important that if a port is not required to be clocked from this 60MHz clock, then it is configured to use another clock block.

U-Series

The XUD library uses two clock blocks (clock blocks 4 and 5). These are clocked from the USB clock. Unlike the G/L devices, clock-block 0 is not used or affected.

Timers

The XUD library allocates and uses four timers.

Memory

The XUD library requires about 9 Kbytes of memory, of which around 6 Kbytes is code or initialized variables that must be stored in either OTP or Flash.

Resource Usage

Ports/Pins

G/L-Series

U-Series

Core Speed

Clock Blocks

G/L-Series

U-Series

Timers

Memory

See Also