Changeset 05015dc1 in rtems

Timestamp:

01/23/18 02:23:55 (5 years ago)

Author:

Chris Johns <chrisj@…>

Branches:

5, master

Children:

5f0a6376

Parents:

4cf93658

git-author:

Chris Johns <chrisj@…> (01/23/18 02:23:55)

git-committer:

Chris Johns <chrisj@…> (02/01/18 03:59:55)

Message:

Xilinx AXI I2C driver IP race condition causes clock glitch.

Setting the PIRQ to 0 before reading the data produces a short clock pulse.
Moving the write to after reading the data fixes the issue.

Close #3173

File:

• cpukit/dev/i2c/xilinx-axi-i2c.c (modified) (1 diff)

cpukit/dev/i2c/xilinx-axi-i2c.c

@@ -513 +513 @@
         xilinx_axi_i2c_disable_clear_irq(bus, INT_TX_ERROR);
         xilinx_axi_i2c_set_cr(bus, CR_TXAK);
+        xilinx_axi_i2c_read_rx_bytes(bus, level);
+        /*
+         * Set the RX PIRQ to 0 after the RX data has been read. There is an
+         * observed timing issue and glitch if written before.
+         */
         xilinx_axi_i2c_write_rx_pirq(bus, 0);
-        xilinx_axi_i2c_read_rx_bytes(bus, level);
         break;