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SC140 DSP Core Reference Manual
Emulation and Debug (EOnCE)
Detection by the event detection channels
Detection of entry into debug mode
Status bit of the ERCV register
Status bit of the ETRSMT register
4.5.6.1.1 Detection by the Event Detection Channels
Each EE signal can be configured to serve as an off-core indication of an event detected by the
corresponding EDCA or by EDCD. The EE signals in this case work as a toggle. A toggle cannot occur in
two consecutive cycles. A toggle can occur in a cycle only if there was no toggle in the preceding cycle.
This capability can be used in the following manner:
Two or more event detection channels of the EOnCE can be programmed to detect certain events.
Each event detection channel toggles its EE signal when the detection of the desired event occurs.
The time elapsed between the two detected events can be measured by connecting the EE signals to
a logic analyzer.
4.5.6.1.2 Detecting Entry into Debug Mode
The EE1 signal can be configured as an indication of debug mode. Each time the core enters debug mode,
the EE1 signal is asserted. On exiting debug mode, the EE1 signal is negated. This technique can be used
as a debug acknowledge.
4.5.6.1.3 Status Bit of the ERCV Register
The EE3 signal can be programmed to serve as an indication that the ERCV register (read by the core) is
empty. This capability provides interrupt driven transfers to the host debugger. If the EE3 signal is
programmed in this way, it is asserted when the host has finished writing to the ERCV register through the
JTAG. It is negated when the core finishes reading the MSB part of the ERCV register.
4.5.6.1.4 Status Bit of the ETRSMT Register
The EE4 signal can be programmed to serve as an indication of data availability in the ETRSMT register.
This capability provides interrupt driven transfers to the host debugger. If the EE4 signal is programmed in
this way, each time the core performs the transfer (and writes to the ETRSMT register), the EE4 signal is
asserted and the host is interrupted. The EE4 signal is negated when the host has finished reading the
ETRSMT register through the JTAG.
4.5.6.2 EE Signals as Inputs
EE signals can be programmed to enable event detection channels or to generate one of the EOnCE events.
After reset, the EE signals are set as inputs. When programmed as an input, an EE signal must be driven
with zero or one. EE assertion can be programmed to perform several functions. For example, EE2 can
enable both EDCA2 and the event counter as well as generate any of the EOnCE events at the same time.
4.5.6.3 Using EE Signals to Enable Event Detection Channels
Each EE signal can be programmed to enable the corresponding address detection channel or the data
detection channel. The user can configure EE0 to enable EDCA0, EE1 to enable EDCA1, EE2 to enable
EDCA2, and so on. EED can also be configured to enable EDCD. For a description of how address event