[src/trunk]: src/sys/dev/ic Add description of the hd64570 chip. Add brief d...

[erh <erh%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/9108e8575e84
branches:  trunk
changeset: 477598:9108e8575e84
user:      erh <erh%NetBSD.org@localhost>
date:      Sat Oct 23 22:20:11 1999 +0000

description:
Add description of the hd64570 chip.  Add brief description of this driver.

diffstat:

 sys/dev/ic/hd64570.c |  30 +++++++++++++++++++++++++++++-
 1 files changed, 29 insertions(+), 1 deletions(-)

diffs (44 lines):

diff -r 024776167cac -r 9108e8575e84 sys/dev/ic/hd64570.c
--- a/sys/dev/ic/hd64570.c      Sat Oct 23 19:34:50 1999 +0000
+++ b/sys/dev/ic/hd64570.c      Sat Oct 23 22:20:11 1999 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: hd64570.c,v 1.6 1999/03/19 22:43:11 erh Exp $  */
+/*     $NetBSD: hd64570.c,v 1.7 1999/10/23 22:20:11 erh Exp $  */
 
 /*
  * Copyright (c) 1998 Vixie Enterprises
@@ -37,6 +37,34 @@
  */
 
 /*
+ * hd64570:
+ *     From the hitachi docs:
+ *     The HD64570 serial communications adaptor (SCA) peripheral chip enables
+ *     a host microprocessor to perform asynchronous, byte-synchronous, or
+ *     bit-synchronous serial communication.  Its two full-duplex,
+ *     multiprotocol serial channels support a wide variety of protocols,
+ *     including frame relay, LAPB, LAPD, bisync and DDCMP.  Its build-in
+ *     direct memory access controller (DMAC) is equipped with a 32-stage
+ *     FIFO and can execure chained-block transfers.  Due to its DMAC and
+ *     16-bit bus interface, the SCA supports serial data transfer rates up
+ *     to 12 Mbits/s without monopolizing the bus, even in full-duplex
+ *     communication.  Other on-chip features of the SCA, including four
+ *     types of MPU interfaces, a bus arbiter, timers, and an interrupt
+ *     controller, provide added functionality in a wide range of
+ *     applications, such as frame relay exchanges/system multiplexes, private
+ *     branch exchanges, computer networks, workstations, ISDN terminals,
+ *     and facsimile.
+ *
+ *     For more info: http://semiconductor.hitachi.com
+ *     ----
+ *
+ *     This driver not only talks to the HD64570 chip, but also implements
+ *     a version of the HDLC protocol that includes the CISCO keepalive
+ *     protocol.  It publishes itself as a network interface that can
+ *     handle IP traffic only.
+ */
+
+/*
  * TODO:
  *
  *     o  teach the receive logic about errors, and about long frames that