3.3.3. Maximum Combined Outstanding Transactions Register

The max_comb_ot Register characteristics are:

Purpose

This register enables you to program the maximum number of address requests for the AR and AW channels. The combined limit is applied after any individual channel limits. See Outstanding transaction regulation for more information.

The outstanding transaction limits have an integer part and a fractional part as follows:

awar_max_oti

Corresponds to the integer part.

awar_max_otf

Corresponds to the binary fraction.

A value of 0 for both the integer and fractional parts disables the programmable regulation so that the configuration limits apply.

The regulation of the combined outstanding transaction limit also requires that you set the en_awar_ot control bit of the QoS control register. See QoS Control Register and Table 3.2.

Usage constraints

You cannot increase the limit above either:

  • the configuration limits you set at design time

  • the CoreLink NIC-400 Network Interconnect limit of 64.

Configurations

Only available when you select outstanding transaction regulation in AMBA Designer.

Attributes

Figure 3.3 shows the bit assignments.

Figure 3.3. max_comb_ot Register bit assignments

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Table 3.4 shows the bit assignments.

Table 3.4. max_comb_ot Register bit assignments

BitsNameFunction
[31:15]-Reserved. Do not modify. Read as zero.
[14:8]awar_max_otiInteger part of the maximum combined outstanding AW and AR addresses.
[7:0]awar_max_otfFractional part of the maximum combined outstanding AW and AR addresses.

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