A_Rqu (Receiving Queue Underrun Register); A_Rqa (Receiving Queue Alert Register); A_Ver (Version Register); A_Cmr (Command Register) - NEC uPD98502 User Manual

4.4.5 A_RQU (Receiving Queue Underrun Register)

A_RQU shows the status of each pool. When a pool has no free buffers, the corresponding bit is set. ATM Cell
Processor detects a pool empty when it receives a cell and try to send the cell to buffer. Whenever one of A_RQU bits
is set, A_RQU bit in A_GSR will be set. In this block, only pool7 to pool0 will be used. If a bit is set to '1',
corresponding pool has no free buffers. Initial value is all zero.
Bits Field
31:8 Reserved
7:0 A_RQU[7:0]

4.4.6 A_RQA (Receiving Queue Alert Register)

A_RQA shows pools with less remaining batches than "ALERT LEVEL", which is set by V
of A_RQA bits is set, A_RQA bit in A_GSR will be set. In this block, only pool7 to pool0 will be used. If a bit is set to
'1', the number of remaining batches is less than "ALERT LEVEL". Initial value is all zero.
Bits Field
31:8 Reserved
7:0 A_RQA[7:0]

4.4.7 A_VER (Version Register)

A_VER shows version number of ATM Cell Processor block. Initial value is 0000_0200H.
Bits Field
31:16 Reserved
15:8 MAJOR
7:0 MINOR

4.4.8 A_CMR (Command Register)

ATM Cell Processor receives command and parameter when V
Cell Processor can handle only one command at a time. When ATM Cell Processor receives a command from
V 4120A, it sets Busy Flag in the register automatically to indicate it is busy. While Busy Flag is set, ATM Cell
R
Processor can not receive a new command. If V
command will be ignored. Initial value is zero. Detail of this register is described in Section 4.7 Commands.
Bits Field
31 BSY
30:0 A_CMR

4.4.9 A_CER (Command Extension Register)

Command Extension Register. Initial value is zero. Detail of this register is described in Section 4.7 Commands.
Bits Field
31:0 A_CER
242
CHAPTER 4 ATM CELL PROCESSOR
R/W Default
R 0 Reserved for future use
R 0 0 = pool [7:0] has free buffers
1 = pool [7:0] has no free buffers
R/W Default
R 0 Reserved for future use
R 0 0 = pool [7:0] has more or equal remaining batches than "ALERT LEVEL"
1 = pool [7:0] has less remaining batches than "ALERT LEVEL"
R/W Default
R 0 Reserved for future use
R 02H Major revision
R 00H Minor revision
4120A writes a new command when Busy Flag is set, the new
R
R/W Default
R/W 0 Busy Flag
R/W 0 Command and parameter
R/W Default
R/W 0 Parameter of command
Preliminary User's Manual S15543EJ1V0UM
Description
Description
Description
4120A writes them in A_CMR and A_CER. ATM
R
Description
Description
4120A. Whenever one
R