31
31
0
Translated address
BASE_ADDR
0
Input virtual address
Physical address translation lookup table
PAT index
Preliminary
Architecture
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2.2.1.4.6 PAT In-Direct Access Translation - Paged Mode Access
DMM_PAT_VIEW[0..3] specify, whether to do Direct or In-direct access translation. Per each of the
8-bit,16-bit ,32-bit and paged container mode, user specifies which LUT to use for address lookup, by
using CONT_x field, in DMM_PAT_VIEW_MAP registers. Then bits [19:12] of input address specify the X
co-ordinate and bits [26:20] of input address specify the Y co-ordinate LUT entry. The PAT replaces
bits[30:12] of input address, with 19-bit value specified in LUT entry.
This translation happens on the 4K page boundary and hence the lower 12 bits are not translated.
describes the actual translation that happens.
Figure 2-5. DMM PAT In-Direct Access Translation
2.2.1.4.7 PAT In-Direct Access Translation - 8-bit, 16-bit, 32-bit Mode Access
DMM_PAT_VIEW[0..3] specify, whether to do Direct or In-direct access translation. Per each of the
8-bit,16-bit ,32-bit and paged container mode, user specifies which LUT to use for address lookup, by
using CONT_x field, in DMM_PAT_VIEW_MAP registers.
How the 26 LSBs of this incoming virtual address is interpreted by the PAT is different for
8-bit,16-bit ,32-bit mode accesses, as compared to the paged mode access described in the preceding
section. Please refer the TILER section describes the rationale behind decoding the address this way.
Virtual address decoding in 8-bit mode access mode is:
•
Bits 0:5 - 6 bits offset into the horizontal line of the page
•
Bits 6:13 - 8 bits, that select horizontal page in the tiler container as well as the X co-ordinate of the
LUT table
•
Bits 14:19 - 6 bits offset to select the line inside the page
•
Bits 20:26 - 7 bits, that select vertical page in the tiler container and also Y co-ordinate of the LUT
table
•
Bits 27:31 - In 8 bit mode, their value is binary (01100), that is address in range
6000 0000h-67FF FFFFh
Virtual address decoding in 16-bit mode access mode is:
•
Bit 0 - is always 0, as accesses are at-least 16-bit aligned
•
Bits 1:6 - 6 bits offset into the horizontal line of the page
•
Bits 7:14 - 8 bits, that select horizontal page in the tiler container as well as the X co-ordinate of the
LUT table
•
Bits 15:19 - 5 bits offset to select the line inside the page
•
Bits 20:26 - 7 bits, that select vertical page in the tiler container and also Y co-ordinate of the LUT
table
•
Bits 27:31 - In 16 bit mode, their value is binary (01101), that is address in range
6800 0000h-6FFF FFFFh
338
DMM/TILER
SPRUGX9 – 15 April 2011
© 2011, Texas Instruments Incorporated