Chapter 18 Enhanced Direct Memory Access (eDMA)
MPC5602P Microcontroller Reference Manual, Rev. 4
412
Freescale Semiconductor
presents a peak transfer rate comparison, measured in MBs per second where the
internal-SRAM-to-internal-SRAM transfers occur at the core’s datapath width; that is, either 32- or 64-bits
per access. For all transfers involving the slave bus, 32-bit transfer sizes are used. In all cases, the transfer
rate includes the time to read the source plus the time to write the destination.
The second performance metric is a measure of the number of DMA requests that can be serviced in a
given amount of time. For this metric, it is assumed the peripheral request causes the channel to move a
single slave-mapped operand to/from internal SRAM. The same timing assumptions used in the previous
example apply to this calculation. In particular, this metric also reflects the time required to activate the
channel. The eDMA design supports the following hardware service request sequence:
•
Cycle 1: eDMA peripheral request is asserted.
•
Cycle 2: The eDMA peripheral request is registered locally in the eDMA module and qualified.
(TCD.START bit initiated requests start at this point with the registering of the slave write to TCD
bit 255).
•
Cycle 3: Channel arbitration begins.
•
Cycle 4: Channel arbitration completes. The transfer control descriptor local memory read is
initiated.
•
Cycle 5–6: The first two parts of the activated channel’s TCD is read from the local memory. The
memory width to the eDMA engine is 64 bits, so the entire descriptor can be accessed in four
cycles.
Table 18-20. eDMA peak transfer rates (MB/Sec)
System Speed,
Transfer Size
Internal SRAM-to-
Internal SRAM
32-bit Slave-to-
Internal SRAM
Internal SRAM-to-
32-bit Slave
(buffering disabled)
Internal SRAM-to-
32-bit Slave
(buffering enabled)
66.7 MHz, 32-bit
66.7
66.7
53.3
88.7
66.7 MHz, 64-bit
133.3
66.7
53.3
88.7
66.7 MHz, 256-bit
1
1
A 256-bit transfer occurs as a burst of four 64-bit beats.
213.4
N/A
2
2
Not applicable: burst access to a slave port is not supported.
83.3 MHz, 32-bit
83.3
83.3
66.7
110.8
83.3 MHz, 64-bit
166.7
83.3
66.7
110.8
83.3 MHz, 256-bit
266.6
N/A
100.0 MHz, 32-bit
100.0
100.0
80.0
133.0
100.0 MHz, 64-bit
200.0
100.0
80.0
133.0
100.0 MHz, 256-bit
320.0
N/A
132.0 MHz, 32-bit
132.0
132.0
105.6
175.6
132.0 MHz, 64-bit
264.0
132.0
105.6
175.6
132.0 MHz, 256-bit
422.4
N/A
Содержание SAFE ASSURE Qorivva MPC5601P
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Страница 128: ...Chapter 6 Power Control Unit MC_PCU MPC5602P Microcontroller Reference Manual Rev 4 128 Freescale Semiconductor ...
Страница 272: ...Chapter 12 e200z0 and e200z0h Core MPC5602P Microcontroller Reference Manual Rev 4 272 Freescale Semiconductor ...
Страница 280: ...Chapter 14 Crossbar Switch XBAR MPC5602P Microcontroller Reference Manual Rev 4 280 Freescale Semiconductor ...
Страница 306: ...Chapter 16 Internal Static RAM SRAM MPC5602P Microcontroller Reference Manual Rev 4 306 Freescale Semiconductor ...
Страница 380: ...Chapter 17 Flash Memory MPC5602P Microcontroller Reference Manual Rev 4 380 Freescale Semiconductor ...
Страница 532: ...Chapter 21 LIN Controller LINFlex MPC5602P Microcontroller Reference Manual Rev 4 532 Freescale Semiconductor ...
Страница 578: ...Chapter 22 FlexCAN MPC5602P Microcontroller Reference Manual Rev 4 578 Freescale Semiconductor ...
Страница 708: ...Chapter 25 FlexPWM MPC5602P Microcontroller Reference Manual Rev 4 708 Freescale Semiconductor ...
Страница 742: ...Chapter 26 eTimer MPC5602P Microcontroller Reference Manual Rev 4 742 Freescale Semiconductor ...
Страница 760: ...Chapter 27 Functional Safety MPC5602P Microcontroller Reference Manual Rev 4 760 Freescale Semiconductor ...
Страница 782: ...Chapter 28 Fault Collection Unit FCU MPC5602P Microcontroller Reference Manual Rev 4 782 Freescale Semiconductor ...
Страница 788: ...Chapter 29 Wakeup Unit WKPU MPC5602P Microcontroller Reference Manual Rev 4 788 Freescale Semiconductor ...
Страница 798: ...Chapter 30 Periodic Interrupt Timer PIT MPC5602P Microcontroller Reference Manual Rev 4 798 Freescale Semiconductor ...
Страница 816: ...Chapter 32 Cyclic Redundancy Check CRC MPC5602P Microcontroller Reference Manual Rev 4 816 Freescale Semiconductor ...
Страница 848: ...Chapter 33 Boot Assist Module BAM MPC5602P Microcontroller Reference Manual Rev 4 848 Freescale Semiconductor ...
Страница 930: ...Chapter 36 Nexus Development Interface NDI MPC5602P Microcontroller Reference Manual Rev 4 930 Freescale Semiconductor ...