Speed up bit-banged USART code in the AVRISP project.
[pub/USBasp.git] / Projects / AVRISP / AVRISP.txt
1 /** \file
2 *
3 * This file contains special DoxyGen information for the generation of the main page and other special
4 * documentation pages. It is not a project source file.
5 */
6
7 /** \mainpage AVRISP MKII Programmer Project
8 *
9 * \section SSec_Compat Project Compatibility:
10 *
11 * The following list indicates what microcontrollers are compatible with this project.
12 *
13 * - Series 7 USB AVRs
14 * - Series 6 USB AVRs
15 * - Series 4 USB AVRs
16 * - Series 2 USB AVRs (8KB versions with reduced features only)
17 *
18 * \section SSec_Info USB Information:
19 *
20 * The following table gives a rundown of the USB utilization of this project.
21 *
22 * <table>
23 * <tr>
24 * <td><b>USB Mode:</b></td>
25 * <td>Device</td>
26 * </tr>
27 * <tr>
28 * <td><b>USB Class:</b></td>
29 * <td>Vendor Specific Class</td>
30 * </tr>
31 * <tr>
32 * <td><b>USB Subclass:</b></td>
33 * <td>N/A</td>
34 * </tr>
35 * <tr>
36 * <td><b>Relevant Standards:</b></td>
37 * <td>Atmel AVRISP MKII Protocol Specification</td>
38 * </tr>
39 * <tr>
40 * <td><b>Usable Speeds:</b></td>
41 * <td>Full Speed Mode</td>
42 * </tr>
43 * </table>
44 *
45 * \section SSec_Description Project Description:
46 *
47 * Firmware for an AVRStudio compatible AVRISP-MKII clone programmer. This project will enable the USB AVR series of
48 * microcontrollers to act as a clone of the official Atmel AVRISP-MKII programmer, usable within AVRStudio. In its
49 * most basic form, it allows for the programming of 5V AVRs from within AVRStudio with no special hardware other than
50 * the USB AVR and the parts needed for the USB interface. If the user desires, more advanced circuits incorporating
51 * level conversion can be made to allow for the programming of 3.3V AVR designs.
52 *
53 * This device spoofs Atmel's official AVRISP-MKII device PID so that it remains compatible with Atmel's AVRISP-MKII
54 * drivers. When prompted, direct your OS to install Atmel's AVRISP-MKII drivers provided with AVRStudio.
55 *
56 * Note that this design currently has several limitations:
57 * - Minimum ISP target clock speed of 500KHz due to hardware SPI used
58 * - No reversed/shorted target connector detection and notification
59 *
60 * On AVR models with an ADC converter, AVCC should be tied to 5V (e.g. VBUS) and the VTARGET_ADC_CHANNEL token should be
61 * set to an appropriate ADC channel number in the project makefile for VTARGET detection to operate correctly. On models
62 * without an ADC converter, VTARGET will report at a fixed 5V level.
63 *
64 * When compiled for the XPLAIN board target, this will automatically configure itself for the correct connections to the
65 * XPLAIN's XMEGA AVR, and will enable PDI only programming support (since ISP mode is not needed).
66 *
67 * While this application can be compiled for USB AVRs with as little as 8KB of FLASH, for full functionality 16KB or more
68 * of FLASH is required. On 8KB devices, either ISP or PDI programming support can be disabled to reduce program size.
69 *
70 * \section Sec_ISP ISP Connections
71 * Connections to the device for SPI programming (when enabled):
72 *
73 * <table>
74 * <tr>
75 * <td><b>Programmer Pin:</b></td>
76 * <td><b>Target Device Pin:</b></td>
77 * <td><b>ISP 6 Pin Layout:</b></td>
78 * </tr>
79 * <tr>
80 * <td>MISO</td>
81 * <td>PDO</td>
82 * <td>1</td>
83 * </tr>
84 * <tr>
85 * <td>ADCx <b><sup>1</sup></b></td>
86 * <td>VTARGET</td>
87 * <td>2</td>
88 * </tr>
89 * <tr>
90 * <td>SCLK</td>
91 * <td>SCLK</td>
92 * <td>3</td>
93 * </tr>
94 * <tr>
95 * <td>MOSI</td>
96 * <td>PDI</td>
97 * <td>4</td>
98 * </tr>
99 * <tr>
100 * <td>PORTx.y <b><sup>2</sup></b></td>
101 * <td>/RESET</td>
102 * <td>5</td>
103 * </tr>
104 * <tr>
105 * <td>GND</td>
106 * <td>GND</td>
107 * <td>6</td>
108 * </tr>
109 * </table>
110 *
111 * <b><sup>1</sup></b> <i>Optional, see \ref SSec_Options section - for USB AVRs with ADC modules only</i> \n
112 * <b><sup>2</sup></b> <i>See \ref SSec_Options section</i>
113 *
114 * \section Sec_PDI PDI Connections
115 * Connections to the device for PDI programming<b><sup>1</sup></b> (when enabled):
116 *
117 * <table>
118 * <tr>
119 * <td><b>Programmer Pin:</b></td>
120 * <td><b>Target Device Pin:</b></td>
121 * <td><b>PDI 6 Pin Layout:</b></td>
122 * </tr>
123 * <tr>
124 * <td>MISO</td>
125 * <td>DATA</td>
126 * <td>1</td>
127 * </tr>
128 * <tr>
129 * <td>ADCx <b><sup>1</sup></b></td>
130 * <td>VTARGET</td>
131 * <td>2</td>
132 * </tr>
133 * <tr>
134 * <td>N/A</td>
135 * <td>N/A</td>
136 * <td>3</td>
137 * </tr>
138 * <tr>
139 * <td>N/A</td>
140 * <td>N/A</td>
141 * <td>4</td>
142 * </tr>
143 * <tr>
144 * <td>PORTx.y <b><sup>2</sup></b></td>
145 * <td>CLOCK</td>
146 * <td>5</td>
147 * </tr>
148 * <tr>
149 * <td>GND</td>
150 * <td>GND</td>
151 * <td>6</td>
152 * </tr>
153 * </table>
154 *
155 * <b><sup>1</sup></b> <i>When PDI_VIA_HARDWARE_USART is set, the AVR's Tx and Rx become the DATA line when connected together
156 * via a pair of 300 ohm resistors, and the AVR's XCK pin becomes CLOCK.</i>
157 *
158 * \section SSec_Options Project Options
159 *
160 * The following defines can be found in this project, which can control the project behaviour when defined, or changed in value.
161 *
162 * <table>
163 * <tr>
164 * <td><b>Define Name:</b></td>
165 * <td><b>Location:</b></td>
166 * <td><b>Description:</b></td>
167 * </tr>
168 * <tr>
169 * <td>RESET_LINE_PORT</td>
170 * <td>Makefile CDEFS</td>
171 * <td>PORT register for the programmer's target RESET line. <i>Ignored when compiled for the XPLAIN board.</i></td>
172 * </tr>
173 * <tr>
174 * <td>RESET_LINE_PIN</td>
175 * <td>Makefile CDEFS</td>
176 * <td>PIN register for the programmer's target RESET line. <i>Ignored when compiled for the XPLAIN board.</i></td>
177 * </tr>
178 * <tr>
179 * <td>RESET_LINE_DDR</td>
180 * <td>Makefile CDEFS</td>
181 * <td>DDR register for the programmer's target RESET line. <i>Ignored when compiled for the XPLAIN board.</i></td>
182 * </tr>
183 * <tr>
184 * <td>RESET_LINE_MASK</td>
185 * <td>Makefile CDEFS</td>
186 * <td>Mask for the programmer's target RESET line on the chosen port. <b>Must not be the AVR's /SS pin</b>, as the
187 * target pins are tri-stated when not in use, and low signals on the /SS pin will force SPI slave mode when the
188 * pin is configured as an input. When in PDI programming mode, this is the target clock pin.
189 * <i>Ignored when compiled for the XPLAIN board.</i></td>
190 * </tr>
191 * <tr>
192 * <td>VTARGET_ADC_CHANNEL</td>
193 * <td>Makefile CDEFS</td>
194 * <td>ADC channel number (on supported AVRs) to use for VTARGET level detection.</td>
195 * </tr>
196 * <tr>
197 * <td>ENABLE_ISP_PROTOCOL</td>
198 * <td>Makefile CDEFS</td>
199 * <td>Define to enable SPI programming protocol support. <i>Ignored when compiled for the XPLAIN board.</i></td>
200 * </tr>
201 * <tr>
202 * <td>ENABLE_PDI_PROTOCOL</td>
203 * <td>Makefile CDEFS</td>
204 * <td>Define to enable XMEGA PDI programming protocol support. <i>Ignored when compiled for the XPLAIN board.</i></td>
205 * </tr>
206 * <tr>
207 * <td>PDI_VIA_HARDWARE_USART</td>
208 * <td>Makefile CDEFS</td>
209 * <td>Define to force the PDI protocol (when enabled) to use the much faster hardware USART instead of bit-banging to
210 * match the official AVRISP pinout. This breaks pinout compatibility with the official AVRISP MKII (and requires
211 * seperate ISP and PDI programming headers) but increases programming speed dramatically.
212 * <i>Ignored when compiled for the XPLAIN board.</i></td>
213 * </tr>
214 * </table>
215 */