PD72042B_15 Datasheet, PDF (73/92 Pages) Renesas Technology Corp – LSI DEVICE FOR Inter Equipment BusTM (IEBusTM) PROTOCOL CONTROL

µPD72042B
Fig. 6-3 Flow of Interrupt Routine
RAWF← 1
TRCF ← MARC
TRRQ ← 1
Start
Disable interrupts from
the µPD72042B
Read FLG
1
RAW?
0
Read RCR
; Program crash?
N
00××
Is return
code in MARC
enabled?
Y
MARC?
010×
; See Note 1.
011×
RERQW ← 1
SIZEW ← RDR1
RECFW ← MARC
RERQW ← 1
SIZEW ← RDR1
RECFW ← MARC
; Classify MARC.
Increment PW
RERQW ← 0
SIZEW ← 0
; Initialize RERQ.
; Initialize SIZE.
TRCF ← SLRC
TRRQ ← 1
N
Is return
code in SLRC
enabled?
; See Note 2.
00××
Y
SLRC?
011×, 101×
010×,
100×
RERQW ← 1
SIZEW ← RDR2
RECFW ← SLRC
RERQW ← 1
SIZEW ← RDR2
RECFW ← SLRC
REEN ← 1
Increment PW
RERQW ← 0
SIZEW ← 0
; Classify SLRC.
; Initialize RERQ.
; Initialize SIZE.
Enable interrupts from
the µPD72042B
RETI
End
Notes 1. The return code in MARC is enabled when any of conditions, 1 , 2 , or 3 , below, is satisfied:
1 MARC has been changed^{Note 3}.
2 MTRQF = 1 and MARQ = 0
3 MRRQF = 1 and MARQ = 0
2. The return code in SLRC is enabled when any of conditions, 1 , 2 , or 3 , below, is satisfied:
1 SLRC has been changed^{Note 3}.
2 STRQF = 1 and STRQ = 0
3 SLREF = 1 and SLRE = 0
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.
Data Sheet S13990EJ3V0DS
71