HD64570 Datasheet, PDF (411/469 Pages) Hitachi Semiconductor – Serial Communications Adaptor

Appendix A Descriptors
Address
Descriptor
CPU CPU
Mode Mode
0, 1 2, 3 Remarks
Chain Pointer L (CPL)
2n 2n+1
Chain Pointer H (CPH)
2n+1 2n
H
L
15
87
0
Buffer Pointer L (BPL)
2n+2 2n+3
CPH
CPL
Buffer Pointer H (BPH)
2n+3 2n+2
B
H
L
23
16 15
87
0
Buffer Pointer B (BPB)
2n+4 2n+5
(Reserved)
2n+5 2n+4
BPB
BPH
BPL
Data Length (DLL)
Data Length (DLH)
Status (ST)
2n+6 2n+7
2n+7 2n+6
2n+8 2n+9
H
L
15
87
0
DLH
DLL
(Reserved)
Status Configuration (transmission)
Bit
Function
7
EOM
6
Not used
5
Not used
4
Not used
3
Not used
2
Not used
1
Not used
0
EOT
Status Configuration (reception)
Bit
Function
7
EOM
6
Short frame
5
Abort
4
Residual bit
3
Overrun
2
CRC
1
Not used
0
Not used
2n+9 2n+8
Rev. 0, 07/98, page 395 of 453