3.7.2. Priority Control Register

The Priority_Ctrl_Reg characteristics are:

Purpose

The Priority_Ctrl_Reg defines the order in which inputs are selected. Each 3-bit field is a priority for each particular slave interface. For example:

Location 0

Has the priority value for the first slave port.

Location 1

Has the priority value for the second slave port.

Location 2

Has the priority value for the third slave port.

...

...

...

...

Location 7

Has the priority value for the eighth slave port.

The values represent the priority value for each port number. If you want to give the highest priority to a particular slave port, program the corresponding port with the lowest value. Typically, this is likely to be a port that has more important data or that has a small FIFO and is therefore likely to overflow. If you want to give lowest priority to a particular slave port, program the corresponding slave port with the highest value. The arbitration logic selects the slave with the lowest port number when the same priority value is entered for multiple slaves.

Usage constraints

Priority values must not be changed while the corresponding slave port is enabled. Before changing the priority level for one or more slave ports, disable those slave ports using the Funnel Control Register.

Configurations

This register is available in all configurations.

The number of fields implemented in this register depends on the configuration of the component.

Attributes

See the register summary in Table 3.33.

Figure 3.30 shows the bit assignments.

Figure 3.30. Priority_Ctrl_Reg bit assignments

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Table 3.35 shows the bit assignments.

Table 3.35. Priority_Ctrl_Reg bit assignments

BitsNameFunction
[31:24]Reserved

-

[23:21]PriPort7

Priority value of the eighth slave port.

[20:18]PriPort6

Priority value of the seventh slave port.

[17:15]PriPort5

Priority value of the sixth slave port.

[14:12]PriPort4

Priority value of the fifth slave port.

[11:9]PriPort3

Priority value of the fourth slave port.

[8:6]PriPort2

Priority value of the third slave port.

[5:3]PriPort1

Priority value of the second slave port.

[2:0]PriPort0

Priority value of the first slave port.


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