Changes between Version 9 and Version 10 of serial

Timestamp:

05/03/2018 04:52:35 PM (6 years ago)

Author:

Tim Harvey

Comment:

updated newport RS485 details

serial

@@ -244 +244 @@
 The following table and sections below provides per-board details of RS485:
 ||= Family  =||= Board                 =||= TXEN  =||= Transceiver =||= Termination =||= Fail-Safe Bias =||= Notes =|| 
-|| Newport   || GW630x                  || gpio12  || [https://www.exar.com/ds/sp335e.pdf SP335E] || optional (gpio16) || included || see [#newport-rs485 newport RS485 below] ||
-|| ||
+|| Newport   || GW630x / GW640x                 || gpio12  || [https://www.exar.com/ds/sp335e.pdf SP335E] || optional (gpio16) || included || ||
 || Ventana   || GW52xx '''(optional)''' || gpio193 || [http://dev.gateworks.com/datasheets/MAX14840E-MAX14841E.pdf MAX14840] || optional     || optional || TIOCSRS485 support ||
 ||           || GW53xx '''(optional)''' || gpio193 || [http://dev.gateworks.com/datasheets/MAX14840E-MAX14841E.pdf MAX14840] || optional     || optional || TIOCSRS485 support ||
@@ -359 +358 @@
 [=#newport-rs485]
 === Newport ===
-The GW630x support optional half-duplex, multi-drop RS585:
- * CN80XX / CN81XX UART2 (/dev/ttyAMA2)
- * [https://www.exar.com/ds/sp335e.pdf SP335E] transceiver
+The GW630x / GW640x have 2 CN80XX UART's (UART2/UART3: /dev/ttyAMA2 and /dev/ttyAMA3) going to a [https://www.exar.com/ds/sp335e.pdf SP335E] transceiver which allows selecting a variety of RS232/RS485 configurations:
+ * 2x RS232 w/o flow control
+ * 1x RS232 w/ flow control
+ * 1x RS485 half duplex
+ * 1x RS485 full duplex
+
+RS485 modes feature:
+ * optional half-duplex, multi-drop RS585:
+ * CN80XX UART2 (/dev/ttyAMA2)
  * optional on-board termination (enabled by gpio16)
  * in-chip fail-safe protection to default idle inputs to logic-high (no external bias resistors required)
  * TXEN connected to gpio12
+
+The pl011 Linux driver supporting the CN80XX serial ports (SERIAL_AMBA_PL011 drivers/tty/serial/amba-pl011.c) does not look like it supports RS485 directly. While this support could be added you can alternatively drive the TXEN gpio12 directly in a user application for RS485 half-duplex.