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UM10503
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© NXP B.V. 2012. All rights reserved.
User manual
Rev. 1.3 — 6 July 2012
606 of 1269
NXP Semiconductors
UM10503
Chapter 24: LPC43xx USB1 Host/Device controller
24.6.8.2 Host mode
This register contains parameters needed for internal TT operations. This register is used
by the host controller only. Writes must be in Dwords.
24.6.9 Burst Size register (BURSTSIZE)
This register is used to control and dynamically change the burst size used during data
movement on the master interface of the USB DMA controller. Writes must be in Dwords.
The default for the length of a burst of 32-bit words for RX and TX DMA data transfers is
16 words each.
24.6.10 Transfer buffer Fill Tuning register (TXFILLTUNING)
24.6.10.1 Device controller
This register is not used in device mode.
24.6.10.2 Host controller
The fields in this register control performance tuning associated with how the host
controller posts data to the TX latency FIFO before moving the data onto the USB bus.
The specific areas of performance include the how much data to post into the FIFO and
an estimate for how long that operation should take in the target system.
Definitions:
T
0
= Standard packet overhead
T
1
= Time to send data payload
T
ff
= Time to fetch packet into TX FIFO up to specified level
T
s
= Total packet flight time (send-only) packet; T
s
= T
0
+ T
1
T
p
= Total packet time (fetch and send) packet; T
p
= T
ff
+ T
0
+ T
1
Table 474. USB TT Control register in host mode (TTCTRL - address 0x4000 715C) bit description
Bit
Symbol
Description
Reset
value
Access
23:0
-
Reserved.
0
-
30:24
TTHA
Hub address when FS or LS device are connected directly.
N/A
R/W
31
-
Reserved.
0
Table 475. USB burst size register in device/host mode (BURSTSIZE - address 0x4000 7160) bit description
Bit
Symbol
Description
Reset
value
Access
7:0
RXPBURST
Programmable RX burst length
This register represents the maximum length of a burst in 32-bit words while
moving data from the USB bus to system memory.
0x10
R/W
15:8
TXPBURST
Programmable TX burst length
This register represents the maximum length of a burst in 32-bit words while
moving data from system memory to the USB bus.
0x10
R/W
31:16
-
reserved
-
-