isp1504a1 NXP Semiconductors, isp1504a1 Datasheet - Page 30

• Manufacturer Part Number: isp1504a1
• Description: Isp1504a1; Isp1504c1 Ulpi Hi-speed Universal Serial Bus On-the-go Transceiver
• Manufacturer: NXP Semiconductors

NXP Semiconductors
ISP1504A1_ISP1504C1_1
Product data sheet
9.5.2.4 RxEvent encoding
OTG devices:
provide a minimum of 8 mA on V
there is no need for an overcurrent detection circuit because the internal A_VBUS_VLD
comparator is sufficient. If the OTG A-device provides more than 100 mA on V
overcurrent detector must be used and
The OTG A-device also uses SESS_VLD to detect when an OTG A-device is initiating
V
When an OTG device is configured as an OTG B-device, SESS_VLD must be used to
detect when V
when V
pulsing SRP.
The RxEvent field (see
packets received on the USB bus. RxActive and RxError are defined in USB 2.0
Transceiver Macrocell Interface (UTMI) Specification Ver. 1.05 . HostDisconnect is defined
in UTMI+ Specification Rev. 1.0 . A short definition is also given in the following
subsections.
Table 16.
RxActive:
an RxActive event to the link. An RxActive event can be communicated using two
methods. The first method is for the ISP1504x1 to simultaneously assert DIR and NXT.
The second method is for the ISP1504x1 to send an RXCMD to the link with the RxActive
field in RxEvent bits set to logic 1. The link must be able to detect both methods. RxActive
frames the receive packet from the first byte to the last byte.
The link must assume that RxActive is set to logic 0 when indicated in an RXCMD or when
DIR is de-asserted, whichever occurs first.
The link uses RxActive to time high-speed packets and ensure that bus turnaround times
are met. For more information on the USB packet timing, see
RxError:
de-asserts NXT and sends an RXCMD with the RxError field set to logic 1. The received
packet is no longer valid and must be dropped by the link.
HostDisconnect:
HostDisconnect is valid only when the ISP1504x1 is configured as a host (both
DP_PULLDOWN and DM_PULLDOWN are set to logic 1), and indicates to the Host
Controller when a peripheral is connected or disconnected. The Host Controller must
enable HostDisconnect by setting the HOST_DISCON_R and HOST_DISCON_F bits in
the USB Interrupt Enable Rising Edge and USB Interrupt Enable Falling Edge registers,
respectively. Changes in HostDisconnect will cause the PHY to send an RXCMD to the
link with the updated value.
Value
00
01
11
10
BUS
pulsing SRP.
BUS
When the ISP1504x1 has detected an error while receiving a USB packet, it
Encoded USB event signals
When the ISP1504x1 has detected a SYNC pattern on the USB bus, it signals
has dropped to a LOW level, allowing the B-device to safely initiate V
BUS
When an OTG device is configured as an OTG A-device, it must be able to
is at a sufficient level for operation. SESS_END must be used to detect
HostDisconnect is encoded into the RxEvent field of the RXCMD.
RxActive
0
1
1
X
Rev. 01 — 6 August 2007
Table
16) of the RXCMD informs the link of information related
BUS
. If the OTG A-device provides less than 100 mA, then
Section “Standard USB Host Controllers”
ISP1504A1; ISP1504C1
RxError
0
0
1
X
ULPI HS USB OTG transceiver
Section
HostDisconnect
0
0
0
1
9.8.1.
© NXP B.V. 2007. All rights reserved.
BUS
BUS
applies.
, an
30 of 80