7.5 Programming the LUT
The contents of the Look Up Table (LUT) can be accessed in several ways that might require different configurations of the autoincrement function of the BLK_IDX register.
The following sections provide examples for programming the LUT.
To read the entire contents of the LUT
- Set the autoincrement enable bit, CTRL.INC_BLK_IDX, to
0b1.
- Read the BLK_MAX register. This register returns the value
0xN, which represents the last address in the LUT.
- Write
0x0 to the BLK_IDX register.
- Perform
0xN + 1 reads of the BLK_LUT register, to read the entire LUT.
To write the entire contents of the LUT
- Set autoincrement enable bit, CTRL.INC_BLK_IDX, to
0b1.
- Read the BLK_MAX register. This register returns the value
0xN, which represents the last address in the LUT.
- Write
0x0 to the BLK_IDX register.
- Perform
0xN + 1 writes to the BLK_LUT register, to fill the entire LUT with your chosen write data. Do not use sparse writes (pstrb != 0xF), otherwise the BLK_IDX does not increment automatically.
To read-modify-write a single location
- Set autoincrement enable bit, CTRL.INC_BLK_IDX, to
0b0.
- Write the required address to the BLK_IDX register.
- Read the BLK_LUT register, to access the current contents of the LUT.
- Write to the BLK_LUT register with your chosen write data.
Byte accesses can be used to update only the required byte of the register without reading the full contents.
Read and write to a 16-block LUT configuration (ADDR_WIDTH - BLK_SIZE = 9)
- Read the contents of the BLK_LUT register, present on bits[15:0].
- Write the new contents to the BLK_LUT register using bits[15:0] only.
Note:
As the number of blocks is less than 32, software cannot use the CTRL.INC_BLK_IDX bit or the BLK_IDX register.
PDF version