Xilinx UG181 manual Sink Static Configuration Interface

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Chapter 2: Core Architecture

Table 2-5:Sink Status FIFO Signals (Continued)

Name	Direction	Clock	Description
		Domain
SnkStatAddr[3:0]	Input	SnkStatClk	Sink Status Address bus: The Sink Status Address determines the
			group of 16-channel status that SnkStat will be updating.
			Bank 0: SnkStatAddr=0, channels 15 to 0
			Bank 1: SnkStatAddr=1, channels 31 to 16
			Bank 2: SnkStatAddr=2, channels 47 to 32
			. . .
			Bank 15: SnkStatAddr=15, channels 255 to 239
SnkStatWr_n	Input	SnkStatClk	Sink Status Write: The Sink Status Write (active low) qualifies the
			SnkStatMask signal. When SnkStatWr_n is asserted (active low),
			status for the different channels is updated. When SnkStatWr_n is
			deasserted (active high), SnkStat input is ignored.
SnkStatMask[15:0]	Input	SnkStatClk	Sink Status Mask Bus: The Sink Status Mask determines if the 2-bit
			status among the corresponding group of 16 channels of status on
			SnkStat (being addressed by SnkStatAddr) will be updated when
			SnkStatWr_n is asserted (active low):
			SnkStatMask[x] = 1, status for channel (x+(SnkStatAddr*16)) will be
			updated.
			SnkStatMask[y] = 0, status for channel (y+(SnkStatAddr*16)) will not
			be updated.
			For example, if SnkStatMask[15] = 1 and SnkStatAddr = 1, then
			SnkStat[31:30] = 00 will overwrite the current status on channel 31. If
			SnkStatMask is all zeros, none of the sixteen 2-bit status values will
			be updated. If SnkStatMask is all ones, all sixteen of the 2-bit status
			values will be updated.

Sink Static Configuration Interface

These signals are inputs to the core that are statically driven by setting them to a constant value in the top-level wrapper file. The SPI-4.2 Lite release includes a wrapper file that has the static configuration signals connected to the values selected in the CORE Generator GUI. Customization of these signals can be done using the GUI.

Two of the Sink Static Configuration signals can be changed in circuit. There are static registers for SnkCalendar_M and SnkCalendar_Len that are synchronous to SnkStatClk. To change these parameters while the core is operational, SnkEn must first be deasserted.

If you sets the configuration signal to an illegal number, the core is automatically set to the minimum value. Table 2-6defines the Sink Static Configuration signals.

26	www.xilinx.com	SPI-4.2 Lite v4.3 User Guide
		UG181 June 27, 2008