The C29x EMIFSS enables devices to
improve access performance using the inherent burst support and dataline buffer for
each CPU. The following tables show the improvement increase for different
accesses.
Table 14-26 SDRAM Sequential Bulk
Transfer
Access Type(1) |
Access Time on C28x (Cycles) |
Access Time on C29x (Cycles) |
C28x:C29x Improvement |
Access Time with DMA (Cycles) |
Access Time with RTDMA (Cycles) |
DMA:RTDMA Improvement |
SDRAM to SRAM 16-bit Access |
8196 |
2821(2) |
2.9X |
9267 |
Not Available(3) |
- |
SDRAM to SRAM 32-bit Access |
5125 |
2564(2) |
2.0X |
4633 |
1125 |
4.1X |
SDRAM to SRAM 64-bit Access |
Not Available |
2559 |
- |
Not Available |
1125 |
- |
SRAM to SRDAM 16-bit Access |
4097 |
4100(2) |
1.0X |
5172 |
Not Available(3) |
- |
SRAM to SDRAM 32-bit Access |
3076 |
2048(2) |
1.5X |
2564 |
1089 |
2.4X |
SRAM to SDRAM 64-bit Access |
Not Available |
1535 |
- |
Not Available |
1093 |
- |
(1) There can be a difference in
timings due to the refresh cycles incurred by the SDRAM
(2) C29x numbers shown for 16-bit and
32-bit accesses are with the read dataline buffer enabled
(3) RTDMA accesses are not supported
for 16-bit transfers in a burst
Table 14-27 SDRAM Random Access
Performance
Access Type |
New Row Access (SYSCLK Cycles) |
Opened Row Access (SYSCLK Cycles) |
8-Bit Read |
20 |
16 |
8-Bit Write |
12 |
8 |
16-Bit Read |
20 |
16 |
16-Bit Write |
12 |
8 |
32-Bit Read |
20 |
16 |
32-Bit Write |
12 |
8 |
64-Bit Read |
24 |
20 |
64-Bit Write |
16 |
12 |
Table 14-28 ASRAM Sequential Bulk Transfer
(1:1:1 Mode)
Access Type |
Access Time on C28x (Cycles) |
Access Time on C29x (Cycles) |
C28x:C29x Improvement |
Access Time with DMA (Cycles) |
Access Time with RTDMA (Cycles) |
DMA:RTDMA Improvement |
ASRAM to SRAM 16-bit Access |
2560 |
2176(1) |
1.2X |
4095 |
Not Available(2) |
- |
ASRAM to SRAM 32-bit Access |
3330 |
1793(1) |
1.9X |
2815 |
1553 |
1.8X |
ASRAM to SRAM 64-bit Access |
Not Available |
1792 |
- |
Not Available |
1553 |
- |
SRAM to ASRAM 16-bit Access |
2561 |
2559(1) |
1.0X |
3583 |
Not Available(2) |
- |
SRAM to ASRAM 32-bit Access |
3327 |
2047(1) |
1.6X |
2559 |
1598 |
1.6X |
SRAM to ASRAM 64-bit Access |
Not Available |
1793 |
- |
Not Available |
1598 |
- |
(1) C29x numbers shown for 16-bit and
32-bit accesses are with the read dataline buffer enabled
(2) RTDMA accesses are not supported
for 16-bit transfers in a burst
Table 14-29 ASRAM Sequential Bulk Transfer
(1:4:1 Mode)
Access Type |
Access Time on C28x (Cycles) |
Access Time on C29x (Cycles) |
C28x:C29x Improvement |
Access Time with DMA (Cycles) |
Access Time with RTDMA (Cycles) |
DMA:RTDMA Improvement |
ASRAM to SRAM 16-bit Access |
4096 |
3712(1) |
1.1X |
5631 |
Not Available(2) |
- |
ASRAM to SRAM 32-bit Access |
4867 |
3329(1) |
1.5X |
4351 |
3089 |
1.4X |
ASRAM to SRAM 64-bit Access |
Not Available |
3328 |
- |
Not Available |
3089 |
- |
SRAM to ASRAM 16-bit Access |
4097 |
4095(1) |
1.0X |
5119 |
Not Available(2) |
- |
SRAM to ASRAM 32-bit Access |
4863 |
3583(1) |
1.4X |
4095 |
3134 |
1.3X |
SRAM to ASRAM 64-bit Access |
Not Available |
3329 |
- |
Not Available |
3134 |
- |
(1) C29x numbers shown for 16-bit and
32-bit accesses are with the read dataline buffer enabled
(2) RTDMA accesses are not supported
for 16-bit transfers in a burst
Table 14-30 ASRAM Random Access
Performance
Access Type |
1:1:1 Configuration (SYSCLK Cycles) |
1:4:1 Configuration (SYSCLK Cycles) |
8-Bit Read |
5 |
8 |
8-Bit Write |
4 |
7 |
16-Bit Read |
5 |
8 |
16-Bit Write |
4 |
7 |
32-Bit Read |
8 |
14 |
32-Bit Write |
7 |
13 |
64-Bit Read |
14 |
26 |
64-Bit Write |
13 |
25 |