7.3.5 Block LUT register, BLK_LUT

The BLK_LUT register controls the Security state of a block. The BLK_LUT register controls up to 32 blocks and the BLK_IDX register sets which 32-block region in the Look Up Table (LUT) is accessed.

Usage constraintsAccessible only from Secure state.
ConfigurationsAvailable in all configurations.
AttributesSee 7.2 Register summary.

The following figure shows the bit assignments.

Figure 7-5 BLK_LUT bit assignments
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The following table shows the bit assignments.

Table 7-6 BLK_LUT bit assignments

Bits Name Default Description
[31:0] BLK_LUT -

Block-based gating Look Up Table (LUT).

Each bit controls the Security state of a single block, but the block number depends on the value of the index pointer, BLK_IDX. For example:

  • If BLK_IDX is 0, then bit[0] contains the Security state of block #0 and bit[31] contains the Security state of block #31.
  • If BLK_IDX is 1, then bit[0] contains the Security state of block #32, bit[31] contains the Security state of block #63.

When:

  • Bit[n] = 0, the block is in the Secure state.
  • Bit[n] = 1, the block is in the Non-secure state.

If auto-increment is enabled, that is CTRL.INC_BLK_IDX == 1, then the MPC increments the BLK_IDX by one, for each word read or word write of the BLK_LUT register.

The reset value of this field depends on the implementation.

If ADDR_WIDTH − BLK_CFG.BLK_SIZE < 10 (LUT contains only 1 register, no LUT address), then the following bits are reserved:

  • bits[31:16] when ADDR_WIDTH − BLK_CFG.BLK_SIZE = 9.
  • bits[31:8] when ADDR_WIDTH − BLK_CFG.BLK_SIZE = 8.
  • bits[31:4] when ADDR_WIDTH − BLK_CFG.BLK_SIZE = 7.
  • bits[31:2] when ADDR_WIDTH − BLK_CFG.BLK_SIZE = 6.
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