NEC mPD98409, Вопросы и ответы

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CHAPTER 7 TRANSMISSION
Information S14769EJ1V0IF00
25
Q.7.6
When are the contents of packet descriptor Word0 stored in transmit VC table Word0?
A.7.6
After the Tx_Ready command has been issued, the
µ
PD98409 reads the packet descriptor and stores the
contents of packet descriptor Word0 in transmit VC table Word0, and then reads the data.
Reference:
µ
PD98409 User’s Manual 5.4.3 (3) Status transition of transmit channel
Q.7.7
Is there a limit to the number of VCs linked to a shaper?
A.7.7
No. It is also possible to link all the VCs used to one shaper.
Reference:
µ
PD98409 User’s Manual 5.4.3 Transmit channel (transmit VC)
Q.7.8
Is there any problem if the value of the vacant field (Word1, Word2 bits 31 to 16) of the transmit packet
descriptor is not 0? Are the values on the system memory rewritten?
A.7.8
The vacant field (Word1, Word2 bits 31 to 16) may be a value other than 0. After reading four words of packet
descriptors, the
µ
PD98409 internally ignores the information in the vacant field. The values on the system
memory are not rewritten.
AAL CLPM PTI GFC S/M D/P
31 29 28 27 26 24 23 20 19 18 17 16 15 0
31 0
CPCS-UU
0
31 16 15 0
31 0
SIZE
MB CPI
7 8
V
0
ADDRESS
C10 IM
Word0
Word1
Word2
Word3
30
Reference:
µ
PD98409 User’s Manual 5.4.2 Structure of transmit data