Freescale Semiconductor MPC8260 - Manual (Page 645)

MPC8260 PowerQUICC II Family Reference Manual, Rev. 2
Freescale Semiconductor 19-1
Chapter 19
SDMA Channels and IDMA Emulation
The PowerQUICC II has two physical serial DMA (SDMA) channels. The CP implements two dedicated
virtual SDMA channels for each FCC, MCC, SCC, SMC, SPI, and I
2 C—one for each transmitter and
receiver. An additional four virtual SDMA channels are assigned to the programmable independent DMA
(IDMA) channels.
Figure 19-1 shows data flow paths. Data from the peripheral controllers can be routed to external RAM
using the 60x bus (path 1) or the local bus (path 2).
Figure 19-1. SDMA Data Paths
On a path 1 access, the SDMA channel must acquire the external system bus. On a path 2 access, the local
bus is acquired and the access is not seen on the external system bus. Thus, the local bus transfer occurs at
the same time as other operations on the external 60x system bus.
External
RAM
External
ROM
Internal 60x Bus
Core
CP SDMA
Dual-Port
RAM
1
3 FCCs
External
RAM
2
60x
Local
2 MCCs 4 SCCs SPI 2 SMCs I 2 C