Host Icu (Perif: Event Unit); Gdma (Direct Memory Access); Gdma Function Description - Siemens ERTEC 200P-2 Manual

2.3.3 Host ICU (PerIF: Event Unit)

The Host Interrupt Controller is included in the Peripherie-IF (see chapter 7.2

2.3.4 GDMA (Direct Memory Access)

2.3.4.1 GDMA Function Description

The GDMA controller is programmable to perform DMA jobs. A DMA job is a collection of
single transfers which are organized in a transfer list. The transfer list contains a parame-
terizable maximum number of single transfers. In the GDMA, the parameter is set to allow
maximally 256 single transfers. A single DMA transfer represents copying of a program-
mable count of data elements, with programmable element size, from source address to
destination address. The number of data elements can be programmed within the range
of 0 to 65535, thus the count of data elements can be set within the range of 1 to 65536
elements. A transfer record of the transfer list defines these parameters of the single
DMA transfer. Each transfer record holds information, whether it is the last one in the job.
The principle of the DMA jobs organization is shown in
The transfer list is saved in the DMA RAM, which is in an internal RAM. The Job List base
address is saved in a GDMA register. The number of transfers per job is programmable;
the maximum number of jobs, supported by the GDMA within ERTEC 200P is 32.
Job List
DMA Jobs:
Job 0
Job 1
Job 2
Job 31
Transfer_lists.vsd
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Technical data subject to change
Transfer List
Transfer Record
Source Addr. 0 Destination Addr. 0
Source Addr. 1 Destination Addr. 1
Source Addr. 2 Destination Addr. 2
Source Addr. 3 Destination Addr. 3
Source Addr. 4 Destination Addr. 4
Source Addr. 5 Destination Addr. 5
Source Addr. 6 Destination Addr. 6
Source Addr. 7 Destination Addr. 7
Source Addr. 250 Destination Addr. 250
Source Addr. 251 Destination Addr. 251
Source Addr. 252 Destination Addr. 252
Source Addr. 253 Destination Addr. 253
Source Addr. 254 Destination Addr. 254
Source Addr. 255 Destination Addr. 255
Figure 1: The principle of the DMA Job organization
103
Figure 1 .
X X
Size 0 Count 0 Last = No
Size 1 Count 1 Last = No
Size 2 Count 2 Last = Yes
Size 3 Count 3 Last = Yes
Size 4 Count 4 Last = No
Size 5 Count 5 Last = No
Size 6 Count 6 Last = No
Size 7 Count 7 Last = Yes
Size 250 Count 250 Last = No
Size 251 Count 251 Last = No
Size 252 Count 252 Last = No
Size 253 Count 253 Last = Yes
Size 254 Count 254 Last = Yes
Size 255 Count 255 Last = Yes
).
X
ERTEC 200P-2 Manual
Version 1.0