Information S14769EJ1V0IF00
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CHAPTER 9 TRANSMISSION/RECEPTION
Q.9.1
Can the contents of the transmit/receive VC table be changed during transmission or reception?
A.9.1
The contents of the VC table cannot be changed during transmission or reception, as changing these may cause
the
µ
PD98409 to malfunction.
Reference:
µ
PD98409 User’s Manual 5.4.3 Transmit channel, 5.5.3 Receive channel
Q.9.2
How many bits can be supported for VPI/VCI?
A.9.2
The transmission side can set and transmit any 24-bit VPI/VCI value. The reception side reduces the 24-bit
VPI/VCI value to 15 bits.
This reduction is done as follows:
VPI is shifted to the VCI side by using the SHIFT value of the VRR register and a 15-bit VPI/VCI value is
generated.
When SHIFT = 0, the 15-bit VCI value is supported.
: Area invalidated by reduction
VPI higher bits
VPI lower bits
VCI higher bits
VCI lower bits
VPI higher bits
VPI lower bits
SHIFT = 4 bits
VCI lower bits
VPI 8 bits
VCI 16 bits
VPI/VCI reduction
When SHIFT = 4
Reference:
µ
PD98409 User’s Manual 3.3 ATM Layer Functions