[common/trigger_io] g_sync_edge should be externable controllable #2

lerwys · 2017-11-29T18:38:38Z

Problem: There are use cases in which we may want to set the synchronizing RX edge of a pulse via an external pin.

Solution: Change the input sync module to one that allows setting the sync_edge by an external driving pin

For AXIS, we must assert the PLD_LAST signal on the last word for a transaction before issuing a new command on the CMD interface. The condition to detect the last word has 2 possibilities: 1) Specified number of words written to the DDR3 controller, typical case in "immediate"" acquisition, and this worked fine. 2) DDR3 AXIS address going over the limit and wrapping back to the start address. This was always asserting the last word detection (ddr_eop signal) on the first word of the next transaction, causing the last word to be written past the DDR3 end address and the next word to be written correctly at the DDR start address. The fix for the case #2 was a simple "=", as we need to consider the case for the DDR end address to be aligned with the "ddr_addr_cnt_axis + c_addr_ddr_inc_axis", which is the condition to the counter to be the last one on the next word. This was reported by Scott Cogan, from FRIB. Thanks Scott.

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[common/trigger_io] g_sync_edge should be externable controllable #2

[common/trigger_io] g_sync_edge should be externable controllable #2

lerwys commented Nov 29, 2017 •

edited

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[common/trigger_io] g_sync_edge should be externable controllable #2

[common/trigger_io] g_sync_edge should be externable controllable #2

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lerwys commented Nov 29, 2017 • edited Loading

lerwys commented Nov 29, 2017 •

edited

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