Chameleon-AVR Nurve Networks, Chameleon-AVR Datasheet - Page 61

• Manufacturer Part Number: Chameleon-AVR
• Description: MCU, MPU & DSP Development Tools AVR8 & PROPELLER DEV SYSTEM (SBC)
• Manufacturer: Nurve Networks

Specifications of Chameleon-AVR

• Processor To Be Evaluated: AVR 328P
• Data Bus Width: 8 bit
• Interface Type: USB, VGA, PS/2, I2C, ISP, SPI
• Operating Supply Voltage: 3.3 V, 5 V
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

STREAM Mode - In stream mode, the mouse sends movement data when it detects movement or a change in state of
one or more mouse buttons. The rate at which this data reporting occurs is the sample rate (defaults to 100 samples/sec
on Reset). This parameter can range from 10 to 200 samples/sec on most drivers. The default sample rate value is 100
samples/sec, but the host may change that value by using the "Set Sample Rate" command. Stream mode is the default
mode of operation following reset.
REMOTE Mode - In this mode the mouse reads its inputs and updates its counters/flags at the current sample rate, but it
does not automatically send data packets when movement occurs, rather the host must “poll” the mouse using the
"Read Data" command. Upon receiving this command the mouse sends back a single movement data packet and resets
its movement counters.
WRAP Mode - This is an "echoing" mode in which every byte received by the mouse is sent back to the host. Even if the
byte represents a valid command, the mouse will not respond to that command -- it will only echo that byte back to the
host. There are two exceptions to this: the "Reset" command and "Reset Wrap Mode" command, this is obviously the
only way to get the mouse back out of the Wrap mode! The mouse treats these as valid commands and does not echo
them back to the host. Thus Wrap mode is a good diagnostic mode to test if a mouse is connected and if its working.
12.2.4 Sending Mouse Commands
A mouse command similar to a keyboard command is sent using the standard 11-bit serial protocol outlined in the
Keyboard Write section. The commands supported are shown in Table 12.7.
Code
$FF
$FE
$F6
$F5
$F4
$F3
Description
Reset - The mouse responds to this command with "acknowledge" ($FA) then enters Reset Mode.
Resend - The host can send this command whenever it receives invalid data from the mouse. The mouse
responds by resending the last packet it sent to the host. If the mouse responds to the "Resend"
command with another invalid packet, the host may either issue another "Resend" command, issue an
"Error" command, cycle the mouse's power supply to reset the mouse, or it may inhibit communication (by
bringing the Clock line low). The action taken depends on the host.
Set Defaults - The mouse responds with "acknowledge" ($FA) then loads the following values into its
driver:
The mouse then resets its movement counters and enters Stream mode.
Disable Data Reporting - The mouse responds with "acknowledge" ($FA) then disables Data Reporting
mode and resets its movement counters. This only effects data reporting in Stream mode and does not
disable sampling. Disabled Stream mode functions the same as Remote mode.
Enable Data Reporting - The mouse responds with "acknowledge" ($FA) then enables Data Reporting
mode and resets its movement counters. This command may be issued while the mouse is in Remote
mode (or Stream mode), but it will only effect data reporting in Stream mode.
Set Sample Rate - The mouse responds with "acknowledge" ($FA) then reads one more byte from the
host which represents the sample rate in unsigned 8-bit magnitude format. The mouse saves this byte as
the new sample rate. After receiving the sample rate, the mouse again responds with "acknowledge"
($FA) and resets its movement counters. Most mice accept sample rates of 10, 20, 40, 60, 80, 100 and
200 samples/sec.
Table 12.7 - Lists the set of command accepted by the standard PS/2 mouse.
Sampling rate = 100.
Resolution = 4 counts/mm.
Scaling = 1:1.
Disable Data Reporting.
© 2009 NURVE NETWORKS LLC “Exploring the Chameleon AVR 8-Bit”
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