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EV80C196KB Microcontroller Evaluation Board User's Manual
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TRAP ISR
This isa pseudo-command. It can not be issued directly by the host software but is
executed when a TRAP instruction is executed. The TRAP instruction is used by
iECM-96 to implement software breakpoints and single stepping. A separate entry
point into the STOP-USER is provided for the TRAP vector. Code at this entry point
sets the TRAP-FLAG and then drops into the code which implements the
STOP-USER command.
REPORT-STATUS (Code 0x14)
This command loads the least significant word of the RISM-DATA register with
status information. Valid status values are:
*O--Indicates that user code is stopped
(RUN-FLAG and TRAP FLAG are both FALSE).
1 --Indicates that user code is running
(RUN-FLAG is TRUE)
2--Indicates that user code executed a TRAP instruction
(TRAP-FLAG is TRUE)
The host software will periodically poll the target system to check on its status and
this polling can rob execution time from the user's program. This loss of target
processor cycles can be avoided by setting the Ring Indicator modem status line
signal whenever the RUN-FLAG is set. The host software will assume that the
target is running user code whenever it detects the ring indicator and will only issue
REPORT-STATUS commands if the ring indicator is off.
MONITOR-ESCAPE (Code 0x15)
This command provides for the addition of RISM commands for special purposes; it
uses the RISM-DATA register to extend the command set of the RISM. The basic
RISM requires only one of these "extended" commands; if the lower 16-bits of the
RISM-DATA register is one (RISM-DATA = OXXXXOOOl H) then the target proces-
sor should execute either a RST (ReSeT) instruction or a software initialization
routine.
Start Up Commands ('I/" or '7")
Upon reset the board is in the echo mode. Until it receives an ASCII slash ('I/") or
reverse-slash ('7") it should increment every character it receives from the host and
send the incremented value back to the host. It will also display the binary code of
the character received on the Port 1 LED's. If a reverse-slash is received by the
RISM it will leave the echo mode (set USER MAP flag true), remap memory and
start normal operation. If a slash is receivedyt will stop echoing incremented re-
ceived data and start responding to RISM commands with the diagnostic flag set. In
this mode there are diagnostic routine resident in EPROM which are useful for
debugging the board. See the -DIAG option under Initiating and Terminating IECM-
96 in the USER INTERFACE section of this manual for additional information on the
Diagnostics Mode.
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