From dc3a6a0ad090df4f6aa8bc21a3d2b48f3715a6f6 Mon Sep 17 00:00:00 2001 From: Josh Blum Date: Thu, 13 Jan 2011 17:01:24 -0800 Subject: usrp1: added docs on missing and emulated features --- host/docs/usrp1.rst | 45 +++++++++++++++++++++++++++++++++++++-------- 1 file changed, 37 insertions(+), 8 deletions(-) (limited to 'host') diff --git a/host/docs/usrp1.rst b/host/docs/usrp1.rst index 9038616a8..44ddb20ca 100644 --- a/host/docs/usrp1.rst +++ b/host/docs/usrp1.rst @@ -4,9 +4,9 @@ UHD - USRP1 Application Notes .. contents:: Table of Contents -^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ +------------------------------------------------------------------------ Specify a non-standard image -^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ +------------------------------------------------------------------------ The standard USRP1 images installer comes with two FPGA images: * **usrp1_fpga.rbf:** 2 DDCs + 2 DUCs * **usrp1_fpga_4rx.rbf:** 4 DDCs + 0 DUCs @@ -66,7 +66,36 @@ Notice that the subdevice name is always specified in the 3 possible cases. B:B ------------------------------------------------------------------------ -OS Specific Notes +Missing and emulated features +------------------------------------------------------------------------ +The USRP1 FPGA does not have the necessary space to support the advanced +streaming capabilities that are possible with the newer USRP devices. +Some of these features are emulated in software to support the API. + +^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ +List of emulated features +^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ +* Setting the current device time +* Getting the current device time +* Transmitting at a specific time +* Receiving at a specific time +* Receiving a specific number of samples + +**Note:** +These emulated features rely on the host system's clock for timed operations, +and therefore may not have sufficient precision for the application. + +^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ +List of missing features +^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ +* Notification on late stream command +* Notification on late transmit packet +* Notification on broken chain error +* Notification on underflow or overflow +* Transmit and receive burst flags + +------------------------------------------------------------------------ +OS specific notes ------------------------------------------------------------------------ ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ @@ -90,13 +119,13 @@ On Windows, a driver must be installed the first time the USRP1 is attached to t A download link for this driver can be found on the UHD wiki page. Download and unpack the driver, and direct the Windows driver install wizard to the .inf file. -^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ -Hardware setup notes -^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ - ------------------------------------------------------------------------ -External Clock Modification +Hardware setup notes ------------------------------------------------------------------------ + +^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ +External clock modification +^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ The USRP can be modified to accept an external clock reference instead of the 64MHz onboard reference. * Solder SMA (LTI-SASF54GT) connector to J2001 * Move 0 ohm 0603 resistor R2029 to R2930 -- cgit v1.2.3