UPD784938 Datasheet, PDF (501/733 Pages) NEC – 16-Bit Single-Chip Microcontrollers

CHAPTER 20 IEBus CONTROLLER
20.5.2 Interrupt source list
The interrupt request signals of the internal IEBus controller in the 78K/IV Series can be classified into vector interrupts
and macro service interrupts. These interrupt processing can be specified through software manipulation.
The interrupt sources are listed below.
Table 20-9. Interrupt Source List
Interrupt Source
Communication error
(Timing error)
(Parity error)
(NACK reception)
(Underrun error)
(Overrun error)
Start interrupt
Status transmission
End of communication
End of frame
Transmit data write
Receive data read
Condition of Generation
CPU Processing after
Remark
Unit
Field
Generation of Interrupt
Master/slave
Reception
Undo communication processing
All fields
Other than data
(individual)
All fields
(broadcasting)
Communication error is OR output
of timing error, parity error, NACK
reception, underrun error, and
overrun error.
Transmission
Other than data
(individual)
Transmission Data
Reception
Data
(broadcasting)
Master
Slave/address
Slave request judgment
Contention judgment
(If loses, remaster processing)
Communication preparation
processing
Interrupt always occurs if loses in
contention during master request.
Slave
Slave/address
Slave request judgment
Communication preparation
processing
Generated only during slave
request
Slave
Control
Refer to transmission processing
example such as slave status.
Generated regardless of the
slave transmission enable flag.
Invalid if flag is disabled.
Transmission Data
Macro service end processing
Set if SCR is cleared to 0
Reception
Data
Macro service end processing
Receive data processing
Set if CCR is cleared to 0
Transmission Data
Retransmission preparation
processing
Set if CCR is cleared to 0
Reception
Data
Re-reception preparation
processing
Set if CCR is cleared to 0
Transmission Data
None (processed by macro
service)
Set after transfering of transmit
data to internal shift register
Reception
Data
None (processed by macro
service)
Set after normal data reception
Preliminary User’s Manual U13987EJ1V0UM00
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