27-10
MPC8260 PowerQUICC II UserÕs Manual
MOTOROLA
Part IV. Communications Processor Module
To enable an interrupt, set the corresponding bit. If a bit is cleared, no interrupt request is
generated and no new entry is written in the circular interrupt table. The user must initialize
INTMSK prior to operation. Reserved bits are cleared.
27.6.3 Channel Mode Register (CHAMR)
The channel mode register (CHAMR) is a user-initialized register, shown in Figure 27-8.
This is a generalized representation of CHAMR. Section 27.7.1, ÒChannel Mode Register
(CHAMR)ÑTransparent Mode,Ó describes the CHAMR for transparent mode.
CHAMR Þelds are described in Table 27-5.
Bits
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
Interrupt Entry
Ñ
UN
TXB
Ñ
NID
IDL
MRF RXF BSY RXB
INTMSK
Ñ
Mask Bits
Ñ
Mask Bits
Figure 27-7. INTMSK Mask Bits
Bits
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
Field
MODE
POL
1
IDLM
Ñ
CRC
Ñ
TS
RQN
NOF
Reset
Ñ
R/W
R/W
Offset
0x1A
Figure 27-8. Channel Mode Register (CHAMR)
Table 27-5. CHAMR Field Descriptions
Bits
Name Description
0
MODE
This mode bit determines whether the HDLC or transparent mode is used. It also determines how
other CHAMR bits are interpreted.
0 Transparent mode. See Section 27.7.1, ÒChannel Mode Register (CHAMR)ÑTransparent Mode.Ó
1 HDLC mode
1
POL
Enable polling. POL enables the transmitter to poll the TxBDs.
0 Polling is disabled (The CPM does not access the external bus to check the R bit in the TxBD).
1 Polling is enabled.
POL can be used to optimize the use of the external bus. Software should always set POL at the
beginning of a transmit sequence of one or more frames. The CP clears POL when no more buffers
are ready in the transmit queue, i.e. when it Þnds a BD with R = 0 (for example, at the end of a frame
or at the end of a multi-frame transmission). To minimize useless transactions on the external bus,
software should always prepare the new BD, or multiple BDs, and set BD[R] before enabling polling.
2
1
Must be set.
Summary of Contents for MPC8260 PowerQUICC II
Page 1: ...MPC8260UM D 4 1999 Rev 0 MPC8260 PowerQUICC II UserÕs Manual ª ª ...
Page 66: ...lxvi MPC8260 PowerQUICC II UserÕs Manual MOTOROLA ...
Page 88: ...1 18 MPC8260 PowerQUICC II UserÕs Manual MOTOROLA Part I Overview ...
Page 120: ...2 32 MPC8260 PowerQUICC II UserÕs Manual MOTOROLA Part I Overview ...
Page 138: ...Part II iv MPC8260 PowerQUICC II UserÕs Manual MOTOROLA Part II Configuration and Reset ...
Page 184: ...4 46 MPC8260 PowerQUICC II UserÕs Manual MOTOROLA Part II ConÞguration and Reset ...
Page 202: ...Part III vi MPC8260 PowerQUICC II UserÕs Manual MOTOROLA Part III The Hardware Interface ...
Page 266: ...8 34 MPC8260 PowerQUICC II UserÕs Manual MOTOROLA Part III The Hardware Interface ...
Page 382: ...10 106 MPC8260 PowerQUICC II UserÕs Manual MOTOROLA Part III The Hardware Interface ...
Page 392: ...11 10 MPC8260 PowerQUICC II UserÕs Manual MOTOROLA Part III The Hardware Interface ...
Page 430: ...Part IV viii MOTOROLA Part IV Communications Processor Module ...
Page 490: ...14 36 MPC8260 PowerQUICC II UserÕs Manual MOTOROLA Part IV Communications Processor Module ...
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Page 980: ...A 4 MPC8260 PowerQUICC II UserÕs Manual MOTOROLA Appendixes ...
Page 1002: ...Index 22 MPC8260 PowerQUICC II UserÕs Manual MOTOROLA INDEX ...
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