TC1796
System Units (Vol. 1 of 2)
System Control Unit
User’s Manual
5-57
V2.0, 2007-07
SCU, V2.0
5.10
Emergency Stop Output Control for GPTA and MSC
The emergency stop feature of the TC1796 allows for a fast emergency reaction on an
external event for the GPTA and MSC modules without the intervention of software. In
an emergency case, the GPTA outputs of the TC1796 can be selectively put immediately
to a well-defined logic level. The two MSC modules, MSC0 and MSC1, are also able to
handle an emergency case by selectively putting bits of the next following serial
downstream frame(s) to a programmable logic value instead of an actual data value.
The emergency case is indicated to the TC1796 by an emergency input signal with
selectable polarity that has to be connected to input HWCFG1 (P10.1).
shows a diagram of the emergency stop input logic. This logic is controlled
by the SCU Emergency Stop Register SCU_EMSR.
Figure 5-13 Emergency Stop Input Control
The emergency stop control logic can basically operate in two modes:
•
Synchronous mode (default after reset):
Emergency case is activated by hardware and released by software.
•
Asynchronous mode:
Emergency case is activated and released by hardware.
MCA05624
P10.1 /
HWCFG1
1
0
1
0
1
EMSF
&
Synchronous Control
Port2
Port3
Port4
Port9
Port8
GPIO Ports
with GPTA
Functionality
MSC0
MSC1
POL
MODE
ENON
EMSFM
Set
Reset
Set
Asynchronous Control
System Control Unit
EMGSTOP
Signal