
401
CHAPTER 17
IEBus CONTROLLER (
PD178096A, 178098A, 178F098 ONLY)
User’s Manual U12790EJ2V0UD
(a) Communication error flag (IEERR)...Bit 6
A flag that indicates the detection of an error during communication.
<Set/reset conditions>
Set:
The flag is set if a timing error, parity error (except in the data field), NACK reception (except in
the data field), underrun error, or overrun error (that occurs during broadcast communication
reception) occurs.
Reset: By software
(b) Start interrupt flag (STARTF)...Bit 5
A flag that indicates whether an interrupt was in the ACK period of the slave address field.
<Set/reset conditions>
Set:
In the slave address field, upon a master request. When the IEBus is a slave unit, this flag is set
upon a request from the master (only if it was a slave request in the locked state from the unit
requesting a lock).
Reset: By software
(c) Status transmission flag (STATUSF)...Bit 4
A flag indicating that the transmission status is either the master to slave status, or the lock address (higher
4 bits, lower 8 bits), when the IEBus is a slave unit.
<Set/reset conditions>
Set:
When 0H, 4H, 5H, or 6H is received in the control field from the master when the IEBus is a slave
unit.
Reset: By software
(d) Communication end flag (ENDTRNS)...Bit 3
A flag that indicates whether communication ends after the number of bytes set in the telegraph length field
have been transferred.
<Set/reset conditions>
Set:
When the value of the IEBus communication success counter (SCR) is 0.
Reset: When the MSTRQ, ENSLVTX, or ENSLVRX flag of IEBus control register 0 (BCR0) is set.
(e) Frame end flag (ENDFRAM)...Bit 2
A flag that indicates whether communication ends after the maximum number of bytes (32 bytes) prescribed
by mode 1 have been transferred.
<Set/reset conditions>
Set:
When the value of the IEBus transmit counter (CCR) is 0.
Reset: When the MSTRQ, ENSLVTX, or ENSLVRX flag of IEBus control register 0 (BCR0) is set.