CD1283 Datasheet, PDF (69/94 Pages) Intel Corporation – IEEE 1284-Compatible Parallel Interface

IEEE 1284-Compatible Parallel Interface — CD1283
7.4.5
7
NegOK
Bit
7
6
5
4
Negotiation Status Register
NSR
Negotiation Status
R/W
6
5
NegFl
HostTO
4
Invalid
29
00
3
2
1
0
4-bit negotiation result code
The results of negotiation attempts are stored in this register.
Description
NegOK: The state of this bit indicates that the negotiation was successful.
Negotiation Failed: The state of this bit indicates that the negotiation failed. The result code indicates which
mode attempted.
Host Timeout: This bit indicates that a host time-out occurred on the parallel channel. The accompanying 4-
bit result code indicates that the link has returned to Compatibility mode (x02). See description of HTVR on
page 59.
Invalid: The state of this bit indicates that the state machine is in an invalid state due to the last negotiation
sequence and has reentered Compatibility mode
The lower 4 bits contain a result code, which shows the current mode.
Bits
3
2
1
0
Description
0
0
0
0 Compatible mode — no negotiation.
0
0
0
1 Failed negotiation.
0
0
1
0 Compatible mode — termination of a 1284 mode.
0
0
1
1
0
1
0
0 Reserved.
0
1
0
1
3:0
0
1
1
0 EPP mode.
0
1
1
1 Reserved.
1
0
0
0 Reverse Nibble mode
1
0
0
1 Reverse Nibble mode — ID request.
1
0
1
0 Reverse Byte mode.
1
0
1
1 Reverse Byte mode — ID request
1
1
0
0 ECP mode without RLE
1
1
0
1 ECP mode without RLE — ID request
1
1
1
0 ECP mode with RLE
1
1
1
1 ECP mode with RLE — ID request
Datasheet
69