Siemens ERTEC 200P-2 Manual page 122

JOB_RESET =
Cancel INTR_EN = 0
HW_FLOW_EN =
HW_JOB_START_EN = 0
JOB_EN =
SW_JOB_START
Parameter assignment of DMA Transfer_Record for SPI operation (receive data):
Source Address
Destination Address =
Transfer Control
Transfer Count
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 =
List (0-255)
JOB_PRIO =
HW_SELECT =
64 inputs)
Copyright © Siemens AG 2016. All rights reserved
Technical data subject to change
0 Reset Job (cancel running job) 0 = don't care, 1 =
Interrupt Request Generation Enable 0 = disabled
1 HW triggered Flow enabled
Start Job by Hardware hier disabled
1 Job Enable
1 Start Job from Software enabled
= 32-bit source address
32-bit destination address
= SOURCE_AMODE = hold address, DEST_AMODE = incr
address, BURST_MODE = Single
= Last Transfer, Enable DMA_ACK, ESIZE = 16, TC = 007Fh
(128 transfers, 16 bit)
0-255
0-31
0
First Transfer Number of Job in Transfer
Job Priority(0-31)
HW Job Start Selector (selects one from
122 ERTEC 200P-2 Manual
Version 1.0