2 This directory contains board specific code for a generic MPC860T based
3 embedded computer, called 'GEN860T'. The design is generic in the sense that
4 common, readily available components are used and that the architecture of the
5 system is i(relatively) straightforward:
7 One eight bit wide boot (FLASH) memory
8 32 bit main memory using SDRAM
11 Some I2C peripheral devices: Atmel AT24C256 EEPROM, Maxim DS1337 RTC.
12 Some other miscellaneous peripherals
14 NOTE: There are references to a XIlinx FPGA and Mil-Std 1553 databus in this
15 port. I guess the computer is not as generic as I first said 8) However,
16 these extras can be safely ignored.
18 Given the GEN860T files, it should be pretty easy to reverse engineer the
19 hardware configuration, if that's useful to you. Hopefully, this code will
20 be useful to someone as a basis for a port to a new system or as a head start
21 on a custom design. If you end up using any of this, I would appreciate
22 hearing from you, especially if you discover bugs or find ways to improve the
23 quality of this U-Boot port.
25 Here are the salient features of the system:
26 Clock : 33 Mhz oscillator
27 Processor core frequency : 66 Mhz if in 1:2:1 mode; can also run 1:1
28 Bus frequency : 33 Mhz
34 Chip : Two Micron MT48LC16M16A2TG-7E
35 CS : MPC860T CS1*/UPMA
46 Chip : One Intel 28F128J3A (StrataFlash)
47 CS : MPC860T CS0*/GPCM (this is the "boot" chip select)
50 Type : Serial I2C EEPROM
53 Chip : One Atmel AT25C256
54 CS : 0x50 (external I2C address pins on device are tied to GND)
57 Type : NAND FLASH (Toshiba)
58 Width : 8 bits (i.e. interface to DOC is 8 bits)
60 Chip : One DiskOnCHip Millenium Plus (DOC 2000+)
61 CS : MPC860T CS2*/GPCM
64 MAC : MPC86OT FEC (Fast Ethernet Controller)
66 MII Addr: 0x0 (hardwired on the board)
70 RS-232 on SMC1 (Maxim MAX3232 LVCMOS-RS232 level shifter)
73 Type : Low power, I2C interface
75 CS : Address 0x68 on I2C bus
77 The MPC860T's internal RTC has a defect in Mask rev D that increases
78 the current drain on the KAPWR line to 10 mA. Since this is an
79 unreasonable amount of current draw for a RTC, and Motorola does not
80 plan to fix this in future mask revisions, a serial (I2C) RTC that
81 works has been included instead. NOTE that the DS1337 can be
82 configured to output a 32768 Hz clock while the main power is on.
83 This clock output has been routed to the MPC860T's EXTAL pin to allow
84 the internal RTC to be used. NOTE also that due to yet another
85 defect in the rev D mask, the RTC does not operate reliably when the
86 internal RTC divisor is set to use a 32768 Hz reference. So just use
90 Xilinx Virtex FPGA on CS3*/GPCM.
91 Virtex FPGA slave SelectMap interface on cs4*/UPMB.
92 Mil-Std 1553 databus interface on CS5*/GPCM.
93 Audio sounder (beeper) with digital volume control connected to SPKROUT.
96 The DOC 2000+ returns 0x40 as its device ID when probed using the method
97 desxribed in the DOC datasheet. Unfortunately, the U-Boot DOC driver
98 does not recognize this device. As of this writing, it seems that MTD
99 does not support the DOC 2000+ either.
102 Everything appears to work except DOC support. As of this writing,
103 David Woodhouse has stated on the MTD mailing list that he has no
104 knowledge of the DOC Millineum Plus and therfore there is no support
105 in MTD for this device. I wish I had known this sooner :(
107 The GEN860T board specific files and configuration is based on the work
108 of others who have contributed to U-Boot. The copright and license notices
109 of these authors have been retained wherever their code has been reused.
110 All new code to support the GEN860T board is:
112 (C) Copyright 2001-2002
113 Keith Outwater (keith_outwater@mvis.com)
115 and the following license applies:
117 This program is free software; you can redistribute it and/or
118 modify it under the terms of the GNU General Public License as
119 published by the Free Software Foundation; either version 2 of
120 the License, or (at your option) any later version.
122 This program is distributed in the hope that it will be useful,
123 WITHOUT ANY WARRANTY; without even the implied warranty of
124 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
125 GNU General Public License for more details.
127 You should have received a copy of the GNU General Public License
128 along with this program; if not, write to the Free Software
129 Foundation, Inc., 59 Temple Place, Suite 330, Boston,
132 Thanks to Wolfgang Denk for a great software package and to everyone
133 who contributed to its development.
138 <keith_outwater@mvis.com>
139 <outwater@eskimo.com>
141 vim: set ts=4 sw=4 tw=78: