NEC UPD98413 User Manual page 120

TXCLK
TXADDR[1:0]
X PORT0
TXCLAV0
TXCLAV1
TXCLAV2
TXCLAV3
TXENB_B
TXDATA[31:0] P12 X
TXPRTY X
TXSOC
X : Invalid
Back-to-back transfer of cells is possible when two cells have to be sent the same port and this port indicates
that it can receive the second cell. In the case of back-to-back transfer the ATM device does not explicitly select
the µPD98413 port and TXENB_B will not be deasserted. The second cell is transferred immediately after the
previous one and the TXSOC is asserted to indicate the start of cell. This example is illustrated below.
Figure 4-6. Back-to-back Cell Transmission (Direct Status Indication)
TXCLK
TXADDR[1:0]
X PORT0
TXCLAV0
TXCLAV1
TXCLAV2
TXCLAV3
TXENB_B
TXDATA[31:0]
P12 X
TXPRTY
X
TXSOC
X : Invalid
120
CHAPTER 4 INTERFACES
Figure 4-5. Transmit Timing (Direct Status Indication)
X
X
X
X
H1 P1 P2 P8
X
X
X
X
H1 P1 P2 P8
PRELIMINARY
X PORT1
P9 P10 P11 P12 X
X
X
P9 P10 P11 P12 H1
NEC confidential and Proprietary
X
X
X
X
X
H1 P1 P2 P3
X
X
X
X
P1 P2 P3 P4