ISP1362BDTM STEricsson, ISP1362BDTM Datasheet - Page 33

• Manufacturer Part Number: ISP1362BDTM
• Manufacturer: STEricsson

Specifications of ISP1362BDTM

• Operating Temperature (min): -40C
• Operating Temperature Classification: Industrial
• Operating Temperature (max): 85C
• Package Type: LQFP
• Rad Hardened: No
• Lead Free Status / RoHS Status: Compliant

ISP1362_7
Product data sheet
10.4.1 Sequence of HNP events
10.4 Host Negotiation Protocol (HNP)
HNP is used to transfer control of the host role between the default host (A-device) and
the default peripheral (B-device) during a session. When the A-device is ready to give up
its role as a host, it will condition the B-device by SetFeature (b_hnp_enable) and will go
into suspend. If the B-device wants to use the bus at that time, it signals a ‘disconnect’ to
the A-device. Then, the A-device will take the role of a peripheral and the B-device will
take the role of a host.
The sequence of events for HNP as observed on the USB bus is illustrated in
As can be seen in
1. The A-device completes using the bus and stops all bus activities (that is, suspends
2. The B-device detects that the bus is idle for more than 5 ms and begins HNP by
3. The A-device detects SE0 on the bus and recognizes this as a request from the
4. After waiting for 30 μs to ensure that the DP line is not HIGH because of the residual
Fig 17. HNP sequence of events
•
•
DP Composite
– Set A_SRP_DET_EN (bit 10) of the OtgControl register to logic 1.
Steps to enable the SRP detection by data line pulsing:
– Set A_SEL_SRP (bit 9) of the OtgControl register to logic 1.
– Set A_SRP_DET_EN (bit 10) of the OtgControl register to logic 1.
Steps to disable the SRP detection:
– Set A_SRP_DET_EN (bit 10) of the OtgControl register to logic 0.
the bus).
turning off the pull-up on DP. This allows the bus to discharge to the SE0 state.
B-device to become a host. The A-device responds by turning on its DP pull-up within
3 ms of first detecting SE0 on the bus.
effect of the B-device pull-up, the B-device notices that the DP line is HIGH and the
DM line is LOW (that is, J state). This indicates that the A-device has recognized the
A-device
B-device
Legend
Figure
Rev. 07 — 29 September 2009
DP driven
Pull-up dominates
Pull-down dominates
Normal bus activity
1
17:
2
3
4
Single-chip USB OTG controller
5
6
7
© ST-ERICSSON 2009. All rights reserved.
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