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Registers
1699
SPRUH82C – April 2013 – Revised September 2016
Copyright © 2013–2016, Texas Instruments Incorporated
Universal Serial Bus 2.0 (USB) Controller
34.4.7 SRP Fix Time Register (SRPFIXTIME)
The SRP fix time register (SRPFIXTIME) allows the CPU to configure the maximum amount of time the
SRP fix logic blocks the Avalid from the PHY to the OTG core. The SRPFIXTIME is shown in
and described in
Figure 34-33. SRP Fix Time Register (SRPFIXTIME)
31
0
SRPFIXTIME
R/W-280 DE80h
LEGEND: R/W = Read/Write; -
n
= value after reset
Table 34-37. SRP Fix Time Register (SRPFIXTIME) Field Descriptions
Bit
Field
Value
Description
31-0
SRPFIXTIME
0-FFFF FFFFh
SRP fix maximum time in 60 MHz cycles. Default is 700 ms (280 DE80h).
34.4.8 Teardown Register (TEARDOWN)
The teardown register (TEARDOWN) controls the tearing down of receive and transmit FIFOs in the USB
controller. When a 1 is written to a valid bit in TEARDOWN, the CPPI FIFO pointers for that endpoint are
cleared. TEARDOWN must be used in conjunction with the CPPI DMA teardown mechanism. The Host
should also write the FLUSHFIFO bits in the TXCSR and RXCSR registers to ensure a complete teardown
of the endpoint.
The TEARDOWN is shown in
and described in
Figure 34-34. Teardown Register (TEARDOWN)
31
21
20
17
16
Reserved
TX_TDOWN
Rsvd
R-0
R/W-0
R-0
15
5
4
1
0
Reserved
RX_TDOWN
Rsvd
R-0
R/W-0
R-0
LEGEND: R/W = Read/Write; R = Read only; -
n
= value after reset
Table 34-38. Teardown Register (TEARDOWN) Field Descriptions
Bit
Field
Value
Description
31-21
Reserved
0
Reserved
20-17
TX_TDOWN
Transmit endpoint teardown. Set the bit that corresponds to the Endpoint (for EP1, set bit 17; for
EP2, set bit 18; for EP3, set bit 19; for EP4, set bit 20).
0
Disable
1
Enable
16-5
Reserved
0
Reserved
4-1
RX_TDOWN
Receive endpoint teardown
0
Disable
1
Enable
0
Reserved
0
Reserved