Infineon Technologies TC1784, Руководство пользователя

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TC1784
Peripheral Control Processor (PCP)
User´s Manual 10-146 V1.1, 2011-05
PCP, V2.09
10.21 PCP Programming Notes and Tips
This section discusses constraints on the use of the PCP and points out some non-
obvious issues.
10.21.1 Notes on PCP Configuration
For configuring of the PCP, some notes should be regarded.
•
Only one Context Model may be used at a time for all channels, and the PCP must
remain in that Context Model once started and configured.
• In order for a specific channel program to be enabled, its context must have
R7.CEN = 1. If R7.CEN = 0, the channel program will terminate when invoked, and
cause a Disabled Channel Request error.
• The Channel Context Address from the FPI Bus as viewed during channel
configuration is as follows:
• Full Context Model: PRAM Base + 20
H
×
n
• Small Context Model: PRAM Base + 10
H
×
n
• Minimum Context Model: PRAM Base + 08
H
×
n
where n is the channel number.
• PCP_CS.RCB and context must be consistent. If RCB is configured to 0, then each
channel program will start at the PC restored from its context. If the wrong address is
pre-configured in the context, the channel program will not operate properly.
• The programmer of the PCP may lock PCP_CS by setting PCP_CS.EIE = 1. When
the global ENDINIT bit is set, the PCP_CS register will no longer be writable, and
attempting to do so will cause an FPI Bus error.
• An error condition will result in an interrupt being sent to the local FPI Bus master.
The targeted interrupt service routine must be capable of dealing with the cause as
recorded in PCP_ES, and, if required, it must be able to return the halted channel
program to operation. The minimum required to do that is to set the context value of
R7.CEN = 1.
• The only PCP Register bit that can be dynamically modified during PCP operation is
the PCP_CS.EN bit. When writing to any other PCP Register bits, the user must
ensure that the PCP is disabled (PCP_CS.EN = 0) and that the PCP is quiescent
(PCP_CS.RS = 0).
10.21.2 General Purpose Register Use
When using the general purpose registers of the PCP, some notes should be regarded.
•
The most significant 16 bits of R7 may not be written, and will always read back as
0. However, no error will occur if a write to the most significant 16 bits occurs.
• Care must be taken with the use of R6 as a general-use register to ensure that R6
contains the correct value prior to execution of the EXIT command. As R6 contains
the CNT1 (counter used in COPY and optionally in EXIT instructions), SRPN and