
CHAPTER 18 IEBus CONTROLLER
Preliminary User’s Manual U17790EJ1V0UD
706
18.5.3 Slave transmission
Initial preparation processing:
Set a unit address, telegraph length, and the first byte of the transmit data.
Communication start processing:
Set the BCR register (enable communication, slave transmission, and slave reception).
Figure 18-28. Slave Transmission
Start
M address P
S address
P
A
Control
P
A
Data 1
PA
Data 1
Data 2
P
A
Data n – 1
P
A
Data n
P
A
<1>
<2>
PA
Approx. 390 s
(mode 1, at 6.29 MHz)
Approx. 624
s (mode 1, at 6.29 MHz)
Broad-
cast
Telegraph
length
<1> Interrupt request signal (INTIE2, INTSTA) occurrence
Judgment of occurrence of error
Note
→
Error processing
↓
Judgment of slave request
<2> Interrupt request signal (INTIE2, INTSTA) occurrence
Judgment of occurrence of error
Note
→
Error processing
↓
Judgment of end of communication
→
End of communication processing
↓
Judgment of end of frame
→
Frame end processing (See 18.5.3 (2) Frame end processing)
Note
This processing is necessary only when the INTIE2 interrupt request signal is used as the start interrupt,
and is not necessary when the INTSTA interrupt request signal is used (in this case, the error processing
is performed by using the INTERR interrupt request signal).
Remarks 1.
: Interrupt request signal (INTIE1) occurrence (See 18.5.3 (1)
Interrupt request signal
(INTIE1) occurrence).
The transmit data of the second and subsequent bytes is written to the DR register by DMA
transfer.
At this time, the data transfer direction is RAM
→ on-chip peripheral I/O.
2.
: An interrupt request signal (INTIE1) does not occur.
3.
: Interrupt request signal (INTIE2) occurrence
An interrupt request signal occurs only when 0H, 4H, 5H, or 6H is received in the control field
in the slave status (for the slave status response operation during the locked status, see 18.3
(11) IEBus control data register (CDR)).
4. n = Final number of data bytes