ISP1301BS,157 NXP Semiconductors, ISP1301BS,157 Datasheet - Page 24

• Manufacturer Part Number: ISP1301BS,157
• Manufacturer: NXP Semiconductors

Specifications of ISP1301BS,157

• Number Of Transceivers: 1
• Esd Protection: YeskV
• Operating Supply Voltage (typ): Not RequiredV
• Operating Temperature Classification: Industrial
• Operating Supply Voltage (max): Not RequiredV
• Operating Supply Voltage (min): Not RequiredV
• Mounting: Surface Mount
• Operating Temperature (max): 85C
• Operating Temperature (min): -40C
• Lead Free Status / RoHS Status: Compliant

ISP1301_5
Product data sheet
10.3 Auto-connect
The Interrupt Latch register bit is cleared by writing logic 1 to its clear address.
The Host Negotiation Protocol (HNP) in the OTG supplement specifies the following
sequence of events to transfer the role of the host from the A-device to the B-device:
The OTG supplement specifies that the time between the B-device de-asserting its DP
pull-up and the A-device asserting its pull-up must be less than 3 ms. For an A-device with
a slow interrupt response time, 3 ms may not be enough time to write an I
command to the ISP1301 to assert the DP pull-up. An alternative method is for the
A-device transceiver to automatically assert the DP pull-up after detecting an SE0 from
the B-device.
The sequence of events is: After finishing data transfers between the A-device and the
B-device and before suspending the bus, the A-device sends SOFs. The B-device
receives these SOFs, and does not transmit any packet back to the A-device. During this
time, the A-device sets the BDIS_ACON_EN bit in the ISP1301. This enables the
ISP1301 to look for SE0 whenever the A-device is not transmitting (that is, whenever the
OE_N/INT_N pin of the ISP1301 is not asserted). After the BDIS_ACON_EN bit is set, the
A-device stops transmitting SOFs and allows the bus to go to the idle state. If the B-device
disconnects, the bus goes to SE0, and the ISP1301 logic automatically turns on the
A-device pull-up.
1. The A-device puts the bus in the suspend state.
2. The B-device simulates a disconnect by de-asserting its DP pull-up.
3. The A-device detects SE0 on the bus, and asserts its DP pull-up.
4. The B-device detects that the DP line is HIGH, and takes the role of the host.
Rev. 05 — 2 September 2009
USB OTG transceiver
© ST-ERICSSON 2009. All rights reserved.
ISP1301
2
C-bus
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