3.3.13. Max OT Registers

The Max OT Registers characteristics are:

Purpose

Determines how many outstanding transactions are permitted when the OT regulator is enabled for each ACE-Lite slave interface. One register exists for each of the S0, S1, and S2 slave interfaces. A value of 0 for both the integer and fractional parts disables the programmable regulation so that the hardware limits apply. A value of 0 for the fractional part disables the regulation of fractional outstanding transactions. If int is the value of the integer part and frac is the value of the fractional part, then:Maximum mean number of outstanding transactions = int + frac/256.

Usage constraints

Setting the maximum outstanding transaction size greater than that configured in the RTL, using the R_MAX or W_MAX parameters, has no effect. Accessible using only Secure accesses, unless you set the Secure Access Register. See Table 3.4.

Configurations

Available in all CCI-400 configurations.

Attributes

Figure 3.12 shows the bit assignments.

Figure 3.12. Max OT Register bit assignments

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Table 3.15 shows the bit assignments.

Table 3.15. Max OT Register bit assignments

Bits

Reset

Access

Function

[31:30]

-

RAZ/WI

Reserved.

[29:24]

0x0

RW

Integer part of the maximum outstanding AR addresses.

[23:16]

0x0

RW

Fractional part of the maximum outstanding AR addresses.

[15:14]

-

RAZ/WI

Reserved.

[13:8]

0x0

RW

Integer part of the maximum outstanding AW addresses.

[7:0]

0x0

RW

Fractional part of the maximum outstanding AW addresses.


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