UM10503
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© NXP B.V. 2012. All rights reserved.
User manual
Rev. 1.3 — 6 July 2012
621 of 1269
NXP Semiconductors
UM10503
Chapter 24: LPC43xx USB1 Host/Device controller
24.6.17 USB Endpoint Setup Status register (ENDPSETUPSTAT)
24.6.18 USB Endpoint Prime register (ENDPTPRIME)
For each endpoint, software should write a one to the corresponding bit whenever posting
a new transfer descriptor to an endpoint. Hardware will automatically use this bit to begin
parsing for a new transfer descriptor from the queue head and prepare a receive buffer.
Hardware will clear this bit when the associated endpoint(s) is (are) successfully primed.
Remark:
These bits will be momentarily set by hardware during hardware endpoint
re-priming operations when a dTD is retired and the dQH is updated.
4
SDIS
Stream disable mode
Remark:
The use of this feature substantially limits the overall USB
performance that can be achieved.
0
R/W
0
Not disabled
1
Disabled.
Setting to a 1 ensures that overruns/underruns of the latency FIFO are
eliminated for low bandwidth systems where the RX and TX buffers are
sufficient to contain the entire packet. Enabling stream disable also has the
effect of ensuring the TX latency is filled to capacity before the packet is
launched onto the USB.
Note: Time duration to pre-fill the FIFO becomes significant when stream
disable is active. See TXFILLTUNING to characterize the adjustments
needed for the scheduler when using this feature.
5
VBPS
VBUS power select
0
R/WO
0
vbus_pwr_select is set LOW.
1
vbus_pwr_select is set
HIGH
31:6
-
-
Reserved
-
-
Table 485. USB Mode register in host mode (USBMODE_H - address 0x4000 71A8) bit description
…continued
Bit
Symbol Value
Description
Reset
value
Access
Table 486. USB Endpoint Setup Status register (ENDPTSETUPSTAT - address 0x4000 71AC) bit description
Bit
Symbol
Description
Reset
value
Access
3:0
ENDPT
SETUP
STAT
Setup endpoint status for logical endpoints.
For every setup transaction that is received, a corresponding bit in this register
is set to one. Software must clear or acknowledge the setup transfer by writing
a one to a respective bit after it has read the setup data from Queue head. The
response to a setup packet as in the order of operations and total response
time is crucial to limit bus time outs while the setup lockout mechanism is
engaged.
0
R/WC
31:4
-
Reserved
-
-