Cirrus Logic EP93xx User Manual
Page 789
DS785UM1
27-19
Copyright 2007 Cirrus Logic
IDE Interface
EP93xx User’s Guide
2
7
2
7
27
Bit Descriptions:
RSVD:
Reserved. Unknown during read, ignored during writes.
HPTR:
Head pointer in the write buffer.
TPTR:
Tail pointer in the write buffer.
EMPTY:
Write buffer empty status.
HOM:
Half or more entries in write buffer filled status.
NFULL:
Write buffer near full status.
FULL:
Write buffer full status.
CRC:
CRC result for data-out operation. Reset to 0x4ABA after
finishing UDMA operation.
IDEUDMARdBufSts
Address:
0x800A_0034 - Read Only
Default:
0000_0100
Definition:
Status register for UDMA read buffer.
Bit Descriptions:
RSVD:
Reserved. Unknown during read, ignored during writes.
HPTR:
Head pointer in the read buffer.
TPTR:
Tail pointer in the read buffer.
EMPTY:
Read buffer empty status.
HOM:
Half or more entries in read buffer filled status.
NFULL:
Read buffer near full status.
FULL:
Read buffer full status.
CRC:
CRC result for data-in operation. Reset back to 0x4ABA
after finishing UDMA operation.
31
30
29
28
27
26
25
24
23
22
21
20
19
18
17
16
CRC
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
RSVD
FULL
NFULL
HOM
EMPTY
TPTR
HPTR