CHAPTER 19 IEBus CONTROLLER (V850/SB2)
User’s Manual U13850EJ6V0UD
568
Figure 19-12. Interrupt Generation Timing (for (2) and (5))
INTIE2
Flag set by reception
of 0H, 4H, 5H, 6H
IEBus sequence
Flag reset by
CPU processing
Error generated by
detection of NACK
Control field
STATUSF flag
Internal NACK flag
Control bits (4 bits)
Parity bit (1 bit)
ACK bit (1 bit)
Terminated by communication error
Because in (4) and (5) the communication was from other than the unit that sent the lock request while
the IEBus was in the locked state, the start or communication complete interrupt (INTIE2) is not
generated, even if the IEBus unit is the communication target. The STATUSF flag (bit 4 of the ISR
register) is set and the status interrupt (INTIE2) generated, however, if a slave status or lock address
request is acknowledged. Note that even if the same control data is received while the IEBus is in the
locked state, the interrupt generation timing for INTIE2 differs depending on whether the master unit (3)
or another unit (4) is requesting the locked state.
Figure 19-13. Timing of INTIE2 Interrupt Generation in Locked State (for (4) and (5))
INTIE2
IEBus sequence
Status
interrupt
Start
Master address
(12 + P)
Broad-
casting
Slave address
(12 + P + A)
Control
(4 + P + A)
Telegraph
length
Note
(8 + P + A)
Data
Note
(8 + P + A)
Note
The telegraph length and data modes are not set in the case of (5) because ACK is not returned.
Remark
P: Parity bit, A: ACK/NACK bit
Содержание V850/SB1
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