Fujitsu MB86R02 Jade-D Hardware Manual page 312

MB86R02 'Jade-D' Hardware Manual V1.64
HOST SCK
HOST XCS
HOST DI CMD
Reset
HOST DO
16.5.1.4.5. Deadlock Scenario
16.1.1.1.3 Situation recognition and recommendations
This section describes a deadlock scenario (at internal points and in the interfaces) of the
MB86R02.
HOST
Soft
TIMER
D.L point T3
Deadlock
point
D.L point R1 in HOST or IF
D.L point R2 in HOST-IF
D.L point R3 in AHB BUS
D.L point T1 in Slave
D.L point T2 in AHB BUS
D.L point T3 in HOST-IF or IF
The MB86R02 device signals the completion of a normal access via the STATUS byte. If a
deadlock situation occurs, the device can be automatically recovered using a watchdog (WDT)
mechanism. The command list can be used to select whether watchdog reactivation is executed
or not.
It is also possible to monitor a MB86R02 deadlock using the timer under the control of the host
CPU software. The host CPU can reset the MB86R02 by using a CMD byte. We strongly
recommend that you use a host CPU issued reset because the the host CPU can not detect a
need Reset Frame
RESET
S
Figure 16-19 Reset Request
D.L point R1
HOST-IF
detect
RS T CMD
D.L point T2
Figure 16-20 Deadlock locations (points)
Cause of
HOST-IF
Deadlock
Idol
Deadlock
waiting resp
waiting resp waiting resp
waiting resp
Deadlock
ABL1 ABL0 DBL2 DBL1 DBL0 R/W CNT1 CNT0
x x x x x
D.L point R2
AHB
D.L point T1
AHB Status to HOST
Idol don't send
Idol or Deadlock
Idol or Deadlock
Deadlock
send wait Sts0
send wait Sts0
Deadlock
send wait Sts0
Deadlock
Idol or Deadlock
1 0
x
RESET
x
RESET
Rx
RDY
D.L point R3
Slave CRG
ALL
RST
Slave
Cmdlist
CCNT
CMDSEQ
Watch Dog
TIMER
INT
Deadlock detection
WDT
Soft TIMER
detect *1 detect
detect detect
detect detect
detect not detect *2
detect not detect *2
detect not detect *2
16-13