4.2.9. Cache Size Selection Register

The CSSELR characteristics are:


Selects the current CCSIDR.

Usage constraints

The CSSELR is:

  • only accessible in privileged modes.

  • banked for Secure and Non-secure states


Available in all configurations.


See the register summary in Table 4.1.

Figure 4.5 shows the CSSELR bit assignments.

Figure 4.5. CSSELR bit assignments

Table 4.6 shows the CSSELR bit assignments.

Table 4.6. CSSELR bit assignments

[31:4]-UNP or SBZ

Cache level selected


There is only one level of cache in the Cortex-A9 processor so the value for this field is b000.


1 = Instruction cache

0 = Data cache.

To access the CSSELR, use:

MRC p15, 2,<Rd>, c0, c0, 0; Read CSSELR
MCR p15, 2,<Rd>, c0, c0, 0; Write CSSELR
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