UPD72042BGT NEC [NEC], UPD72042BGT Datasheet - Page 71

• Manufacturer Part Number: UPD72042BGT
• Description: LSI DEVICE FOR Inter Equipment Bus (IEBus) PROTOCOL CONTROL
• Manufacturer: NEC [NEC]

Notes 1. The return code in MARC is enabled when any of conditions, 1 , 2 , or 3 , below, is satisfied:
2. The return code in SLRC is enabled when any of conditions, 1 , 2 , or 3 , below, is satisfied:
3. When MARC is 0001 or 0101, the same value may be generated consecutively, such that MARC is set
to 1111 to enable the detection of a change in MARC the next time it is generated. When SLRC is 0001,
0101, or 1001, it is again set to 1111 for the same reason.
1 MARC has been changed
2 MTRQF = 1 and MARQ = 0
3 MRRQF = 1 and MARQ = 0
1 SLRC has been changed
2 STRQF = 1 and STRQ = 0
3 SLREF = 1 and SLRE = 0
TRCF
TRRQ
TRCF
TRRQ
RAWF
MARC
1
SLRC
1
1
Fig. 6-3 Flow of Interrupt Routine
00
00
Note 3
N
N
Note 3
Disable interrupts from
Enable interrupts from
Data Sheet S13990EJ3V0DS
1
RERQ
SIZE
RECF
RERQ
SIZE
RECF
the PD72042B
the PD72042B
.
.
code in MARC
code in SLRC
Read FLG
Read RCR
MARC?
W
W
SLRC?
enabled?
RAW?
Is return
enabled?
Is return
W
W
W
W
RETI
Start
End
0
RDR1
RDR2
010
010 ,
100
Y
Y
MARC
SLRC
1
1
011
011 , 101
; Program crash?
; See Note 1.
; See Note 2.
RERQ
SIZE
RECF
RERQ
SIZE
RECF
Increment PW
RERQ
SIZE
Increment PW
RERQ
SIZE
REEN
W
W
W
W
W
W
W
W
W
W
RDR1
RDR2
MARC
0
0
1
SLRC
1
0
0
1
; Classify MARC.
; Initialize RERQ.
; Initialize SIZE.
; Classify SLRC.
; Initialize RERQ.
; Initialize SIZE.
PD72042B
71