Port control register – Digi NS9750 User Manual
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I E E E 1 2 8 4 P e r i p h e r a l C o n t r o l l e r
Port Control register
Address: 9040 0108
Note:
The Port Control register can control IEEE 1284 pins only if no modes are
enabled in the Master Enable register (see"Master Enable register" on page
697).
Register bit assignment
Bits
Access
Mnemonic
Reset
Description
D31:08
N/A
Reserved
N/A
N/A
D07
R/W
BUSY
0x0
Allows the CPU to directly control the IEEE 1284 pin
values.
The meaning of each bit varies, depending on whether the
mode is compatibility, nibble, byte, or ECP.
Notes:
Bits [07:03] should be set to 1 before the printer is
enabled (ecr[0]=’1’) to avoid driving IEEE 1284 pins
during initialization.
AutoNegotiate and AutoTransfer must be turned off
before software can take control of these control
signals (see "Master Enable register" on page 697).
D06
R/W
N_ACK
0x0
D05
R/W
PERR
0x0
D04
R/W
SEL
0x0
D03
R/W
N_FLT
0x0
D02:00
N/A
Reserved
N/A
N/A
Table 401: pcr — Port Control register
BUSY N_ACK PERR
SEL
N_FLT
13
12
11
10
9
8
7
6
5
4
3
2
1
0
15
14
31
29
28
27
26
25
24
23
22
21
20
19
18
17
16
30
Reserved
Reserved
Reserved