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Fixed ambiguity of "read" vs "write". #33

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Merged
GrantMeStrength merged 2 commits into from
Feb 27, 2020
Merged

Fixed ambiguity of "read" vs "write". #33

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9eb34f9
Fixed ambiguity of "read" vs "write".
paamand Jan 8, 2020
e8147a0
Merge branch 'docs' into patch-2
GrantMeStrength Feb 27, 2020
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5 changes: 3 additions & 2 deletions sdk-api-src/content/winusb/nf-winusb-winusb_readisochpipeasap.md
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Expand Up @@ -110,8 +110,9 @@ If the caller sets <i>ContinueStream</i> to TRUE, The transfer fails if Winusb.s
<b>WinUsb_ReadIsochPipeAsap</b> allows the USB driver stack to choose the starting frame number for the transfer. If one or more transfers are already pending on the endpoint, the transfer will be scheduled for the frame number immediately following the last frame number of the last currently pending transfer.


<b>WinUsb_ReadIsochPipeAsap</b> packetizes the transfer buffer so that in each 1ms interval, the host can receive the maximum bytes allowed per interval. The maximum bytes is as specified by the endpoint descriptor for full and high-speed endpoints, and endpoint companion descriptor for SuperSpeed endpoints.
If the caller submits multiple read requests to stream data to the device, the transfer size should be a multiple of the maximum bytes per interval (as returned by <a href="https://docs.microsoft.com/windows/desktop/api/winusb/nf-winusb-winusb_querypipeex">WinUsb_QueryPipeEx</a>) * 8 / interval.
<b>WinUsb_ReadIsochPipeAsap</b> packetizes the transfer buffer so that in each interval, the host can receive the maximum bytes allowed per interval. The maximum bytes is as specified by the endpoint descriptor for full and high-speed endpoints, and endpoint companion descriptor for SuperSpeed endpoints.
If the caller submits multiple read requests to stream data from the device, the transfer size should be a multiple of the maximum bytes per interval (as returned by <a href="https://docs.microsoft.com/windows/desktop/api/winusb/nf-winusb-winusb_querypipeex">WinUsb_QueryPipeEx</a>) * 8 / interval.



Because of the transfer packaging used in the underlying kernel-mode interface, the lowest latency notification to an application or driver is 1ms intervals.
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