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CS4210 Datasheet, PDF (87/102 Pages) National Semiconductor (TI) – IEEE 1394 OHCI Controller
Register Descriptions (Continued)
Bit
31
30
29
28
27:16
15
14:13
12
11
10
9:8
7:5
4:0
Table 4-53. IsochRxnContextControl Set/Clear Register
Name
bufferFill
Access
RSC
isochHeader
RSC
cycleMatchEnable RSCU
multiChanMode
RSC
RSVD
run
--
RSCU
RSVD
wake
dead
active
RSVD
spd
event code
--
RSU
RU
RU
--
RU
RW
Reset
Undef
Undef
Undef
Undef
0
0
0
Undef
0
0
0
Undef
Undef
Description
Buffer Fill: When set to one, received packets are placed back-to-back to
completely fill each receive buffer (specified by an INPUT_MORE com-
mand). When clear, each received packet is placed in a single buffer
(described by zero to seven INPUT_MORE commands followed by an
INPUT_LAST command). If the multiChanMode bit (bit 28) is set to one,
this bit must also be set to one. The value of bufferFill must not be changed
while active (bit 10) or run (bit 15) are set to one.
Isochronous Header: When set to one, received isochronous packets
include the complete 4-byte isochronous packet header seen by the Link
layer. The end of the packet is marked with a xferStatus (bits 15:0 of this
register) in the first doublet, and a 16-bit timeStamp indicating the time of
the most recently received (or sent) cycleStart packet. When clear, the
packet header is stripped off of received isochronous packets. The packet
header, if received, immediately precedes the packet payload. Details are in
the 1394 OHCI specification data formats. The value of isochHeader must
not be changed while active or run are set to one.
Cycle Match Enable: In general, when set to one, the context begins run-
ning only when the 15-bit cycleMatch field in the corresponding IsochRxn-
ContextMatch register matches the two sets of bits of the bus
IsochCycleTimer.cycleSeconds and 13-bit IsochCycleTimer.cycleCount val-
ues (BAR0+Offset F0h). The effects of this bit are impacted by the values of
other bits in this register and are explained in Section 4.4.26.1 "Isoch Trans-
mit Context Control Register" on page 84. Once the context has become
active, hardware clears the cycleMatchEnable bit. The value of cycleMatch-
Enable must not be changed while active or run are set to one.
Multiple Channel Mode: When set to one, the corresponding isochronous
receive DMA context receives packets for all isochronous channels enabled
in the IRChannelMaskHi and IRChannelMaskLo registers (Section 4.4.15
"IRMultiChanMask Registers" on page 69). The isochronous channel num-
ber specified in the corresponding IsochRxnContextMatch register is
ignored. When set to zero, the IRDMA context receives packets for that sin-
gle channel. Only one IRDMA context may use the IRChannelMask regis-
ters. If more than one IsochRxContextControl register has the
multiChanMode bit set, results are undefined. The value of multiChanMode
must not be changed while active or run are set to one
Reserved
Run: The run bit is set by software to enable descriptor processing for a
context and cleared by software to stop descriptor processing. The CS4210
only clears this bit on a hardware or software reset. See Section 3.3.2.1
"ContextControl.run" on page 21 for details.
Reserved
Wake: Software sets this bit to 1 to cause the CS4210 to continue or
resume descriptor processing. The CS4210 clears this bit on every descrip-
tor fetch. See Section 3.3.2.2 "ContextControl.wake" on page 21 for details.
Dead: The CS4210 sets this bit when it encounters a fatal error and clears
this bit when software clears the run bit. See Section 3.3.2.4 "ContextCon-
trol.dead" on page 21 for details.
Active: The CS4210 sets this bit to 1 when it is processing descriptors. See
Section 3.3.2.3 "ContextControl.active" on page 21 for details.
Reserved
Speed: This field indicates the speed at which the packet was received.
000 = 100 Mbits/sec, 001 = 200 Mbits/sec, and 010 = 400 Mbits/sec. All
other values are reserved.
Event Code: For bufferFill mode, possible values are: ack_complete,
evt_descriptor_read, evt_data_write, and evt_unknown. Packets with data
errors and packets for which a FIFO overrun occurred are ‘backed-out’ by
reverting to the previous state and Xferstatus and resCount are not
updated. For packet-per-buffer mode, possible values are: ack_complete,
ack_data_error, evt_long_packet, evt_overrun, evt_descriptor_read,
evt_data_write, and evt_unknown.
Revision 1.0
87
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