Fujitsu MB86R02 Jade-D Hardware Manual page 313

MB86R02 'Jade-D' Hardware Manual V1.64
WDT issued reset. The host CPU should therefore detect abnormal operation of the MB86R02
and reacivate it itself.
16.5.1.4.6. Reactivation process
If the status is not returned because the AHB-BUS and the slave device are deadlocked, the host
CPU can insert an RST request in the CMD byte during transmission. The figure below shows
the deadlock reactivation process.
Start
t
CMD AB#n
Beginning of
data transfer
Software TIMER of HOST
Start of
software timer
The response from the HOSTIF module is monitored using the software timer which is managed
by the host CPU.
The MB86R02 is reactivated from a deadlock by asserting a RST from the host CPU if there has
been no response for a set time (e.g. for 0.5 seconds).
16-14
CMD CMD CMD CMD
(DmyWri te (DmyWri te (DmyWri te (DmyWri te
STATUS STATUS STATUS STATUS
Rea dSts 0 Rea dSts 0 Rea dSts 0 Rea dSts 0
The response is being waited for with the software timer
Figure 16-21 Deadlock reactivation process
ABL1 ABL0 DBL2 DBL1 DBL0 R/W
X X X X
CMD CMD CMD
(DmyWri te (DmyWri te (DmyWri te (DmyWri te
STATUS STATUS STATUS
Rea dSts 0 Rea dSts 0 Rea dSts 0
The deadlock happened !!
Time out!(e.g 0.5sec)
detects there is no response from Indigo.
<-- Control with software
Reboot
CNT1 CNT0
Indigo
X X "1" "0"
CMD CMD CMD
Reset
(DmyWri te (RST req)
Fram e
STATUS STATUS STATUS STA
Rea dSts 0 Rea dSts 0 Rea dSts 0
Reset is
demanded.
The software timer