Copyright © Siemens AG 2016. All rights reserved
122
ERTEC 200P-2 Manual
Technical data subject to change
Version 1.0
JOB_RESET =
0
Reset Job (cancel running job) 0 = don’t care, 1 =
Cancel INTR_EN = 0
Interrupt Request Generation Enable 0 = disabled
HW_FLOW_EN
= 1
HW triggered Flow enabled
HW_JOB_START_EN = 0
Start Job by Hardware hier disabled
JOB_EN =
1
Job Enable
SW_JOB_START 1
Start Job from Software enabled
Parameter assignment of DMA Transfer_Record for SPI operation (receive data):
Source Address
=
32-bit source address
Destination Address =
32-bit destination address
Transfer Control =
SOURCE_AMODE = hold address, DEST_AMODE = incr
address, BURST_MODE = Single
Transfer Count =
Last Transfer, Enable DMA_ACK, ESIZE = 16, TC = 007Fh
(128 transfers, 16 bit)
The address remains the same in source address mode as the data from the SPI receive
FIFO are always read at the same address. For writing DMA data to PN-RAM, however,
incremental address mode is set. The transfer counter (TC) is set to the number of trans-
fers to be carried out, for example 128. If the number changes, Tranfer_Record must be
reconfigured. If the TC reaches zero, all data should have been transferred and the job is
complete.
Only one transfer record is likely to be needed.
2.3.4.2.1.3 Transmit Data
The SPI has been switched to master mode by the SW parameter assignment. The SW
then starts the DMA job.
The job is started by the SW (Job started) and starts to run when the DMA request sig-
nals are queried (job is running); that is why the SW_JOB_START bit is set to 1.
The data are written to the transmit FIFO of the SPI-IP by the DMA as soon as the DMA
transmit request signal becomes active (TFE=Transmit-FIFO empty). To avoid a FIFO
overflow, a maximum of 4 halfwords are written to the 8-entry deep FIFO (INCR4). Trans-
fer is in an 8-byte INCR4 burst. As soon as the first data item is written to the FIFO, the
TFE signal becomes inactive and transfer is interrupted after the 8 bytes. As soon as the
data have been sent, the signal is activated again and the next 8 bytes can be trans-
ferred.
Configuring the JOB_CTL Register and Transfer_Record
Sending data
of different lengths from
2 to 256 bytes
. Controlling DMA traffic with SPI
DMA-REQ. Data are read by the DMA from PN-RAM, for example, and written to the
transmit FIFO of the SPI. The data bus width of the SPI is 16 bits. JOB_CTL register1 is
linked to DMA_ACK1, which is connected to SPI_TFE (Transmit Buffer empty).
Entries required in
Job Control Register 1
(SPI transmit data):
TRANSFER_PTR = 0-255
First Transfer Number of Job in Transfer
List (0-255)
JOB_PRIO =
0-31
Job Priority(0-31)
HW_SELECT =
0
HW Job Start Selector (selects one from
64 inputs)