ISP1160
Embedded USB Host Controller
Philips Semiconductors
Table 5:
Philips Transfer Descriptor (PTD): bit description
Symbol
Access
R/W
Description
Contains the number of bytes that were transferred for this PTD.
ActualBytes[9:0]
CompletionCode[3:0]
R/W
0000 NoError
General TD or isochronous data packet processing
completed with no detected errors.
0001 CRC
Last data packet from endpoint contained a CRC error.
0010 BitStuffing
Last data packet from endpoint contained a bit stuffing
violation.
0011 DataToggleMismatch
0100 Stall
Last packet from endpoint had data toggle PID that did
not match the expected value.
TD was moved to the Done queue because the
endpoint returned a STALL PID.
0101 DeviceNotResponding Device did not respond to token (IN) or did not provide a
handshake (OUT).
0110 PIDCheckFailure
0111 UnexpectedPID
1000 DataOverrun
Check bits on PID from endpoint failed on data PID (IN)
or handshake (OUT).
Received PID was not valid when encountered or PID
value is not defined.
The amount of data returned by the endpoint exceeded
either the size of the maximum data packet allowed
from the endpoint (found in the MaximumPacketSize
field of endpoint descriptor) or the remaining buffer size.
1001 DataUnderrun
The endpoint returned is less than MaximumPacketSize
and that amount was not sufficient to fill the specified
buffer.
1010 reserved
-
-
1011 reserved
1100 BufferOverrun
During an IN, the HC received data from an endpoint
faster than it could be written to system memory.
1101 BufferUnderrun
During an OUT, the HC could not retrieve data from the
system memory fast enough to keep up with the USB
data rate.
Active
R/W
Set to logic 1 by firmware to enable the execution of transactions by the HC. When the
transaction associated with this descriptor is completed, the HC sets this bit to logic 0,
indicating that a transaction for this element will not be executed when it is next
encountered in the schedule.
Toggle
R/W
R
Used to generate or compare the data PID value (DATA0 or DATA1). It is updated after
each successful transmission or reception of a data packet.
MaxPacketSize[9:0]
The maximum number of bytes that can be sent to or received from the endpoint in a
single data packet.
EndpointNumber[3:0]
R
R
R
USB address of the endpoint within the function.
Last PTD of a list (ITL or ATL). Logic 1 indicates that the PTD is the last PTD.
Speed of the endpoint:
Last
Speed
0 — full speed
1 — low speed
TotalBytes[9:0]
R
Specifies the total number of bytes to be transferred with this data structure. For Bulk and
Control only, this can be greater than MaximumPacketSize.
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© Koninklijke Philips Electronics N.V. 2003. All rights reserved.
Product data
Rev. 04 — 04 July 2003
21 of 88
NXP [ NXP ]
