CHAPTER 19 IEBus CONTROLLER (V850/SB2)
User’s Manual U13850EJ4V0UM
486
19.5.3 Slave transmission
Initial preparation processing:
Sets a unit address, telegraph length, and the first byte of the transmit data.
Communication start processing:
Sets the bus control register (enables communication, slave transmission, and slave reception).
Figure 19-32. Slave Transmission
Start
M address P
S address
P
A
Control
P
A
Data 1
P
A
Data 1
Data 2
P
A
Data n – 1
P
A
Data n
P
A
<1>
<2>
P
A
Approx. 390 s
(mode 1)
Approx. 624 s (mode 1)
µ
µ
Broad-
casting
Telegraph
length
<1> Interrupt (INTIE2) occurrence
Judgment of occurrence of error
→
Error processing
↓
Judgment of slave request
<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
→
Frame end processing (See
19.5.3 (2) Frame end
processing
)
Remarks 1.
: Interrupt (INTIE1) occurrence (See
19.5.3 (1) 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.
: Interrupt (INTIE2) occurrence
An interrupt 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 locked, refer to
19.3.2 (5) IEBus
control data register (CDR)
).
4.
n = Final number of data bytes
