![NEC V850/SC1 Скачать руководство пользователя страница 550](http://html.mh-extra.com/html/nec/v850-sc1/v850-sc1_user-manual_248178550.webp)
CHAPTER 18 IEBus CONTROLLER (V850/SC2)
548
User’s Manual U15109EJ3V0UD
18.5 Interrupt Generation Timing and Main CPU Processing
18.5.1 Master transmission
Initial preparation processing:
Sets a unit address, slave address, control data, telegraph length, and the first byte of the transmit data.
Communication start processing:
Sets the bus control register (enables communication, master request, and slave reception).
Figure 18-17. Master Transmission
Start
Broad-
casting
M address P
S address
P
A
Control
P
A
Telegraph
length
P
A
Data 1
P
A
Data 1
Data 2
P
A
Data n
−
1
P
A
Data n
P
A
<1>
<2>
Approx. 624 s (mode 1)
Approx. 390 s
(mode 1)
µ
µ
<1> Interrupt (INTIE2) occurrence
Judgment of occurrence of error
→
Error processing
↓
Judgment of slave request
→
Slave reception processing
(See
18.5.1 (1) Slave reception processing
)
↓
Judgment of contention result
→
Remaster request processing
<2> Interrupt (INTIE2) occurrence
Judgment of occurrence of error
→
Error processing
↓
Judgment of end of communication
→
End of communication processing
↓
Judgment of end of frame
→
Re-communication processing
(See
18.5.1 (3) Re-communication processing
)
Remarks 1.
: Interrupt (INTIE1) occurrence (See
18.5.1 (2) Interrupt (INTIE1) occurrence
)
The transmit data of the second byte and those that follow are written to the IEBus data
register (DR) by DMA transfer.
At this time, the data transfer direction is RAM (memory)
→
SFR (peripheral)
2.
: An interrupt (INTIE1) does not occur.
3.
n = Final number of data bytes