Sundance SMT335E - Manual (Page 36)

Version 1.5 Page 36 of 53 SMT335E SMT375E User Manual
CONFIG & NMI
The TIM specification describes the operation of an open-collector type signal
CONFIG that is driven low after reset.
This signal, on a standard C4x based TIM, is connected to the processor’s IIOF3 pin.
On the SMT335E/375, the CONFIG signal is asserted after power on, and can be
released by writing the value (1<<7) to the config register. Conversely, CONFIG may
be re-asserted by writing 0 to this bit. It is not possible for software to read the state
of the CONFIG signal.
The NMI signal from the TIM connector can be routed to the C6000 NMI pin.
WARNING: Several software components include code sequences that assume
setting GIE=0 in the C6000 CSR will inhibit all interrupts; NMI violates that
assumption. If an NMI occurs during such code sequences it may not be safe to
return from the interrupt. This may be particularly significant if you are using the
compiler’s software pipelining facility.
Config Register
TIMCONFIG 0x03C80000
31–8 7 6 5–0
NMI EN TRI CONF
RW,0 RW,0
Field Description
0 drive CONFIG low
TRICONF
1 tri-state CONFIG
0 Disconnect NMI from the C6000
NMIEN
1 Connect NMI from TIM to the C6000.