Datasheet

PICkit™ Serial Analyzer User’s Guide
DS51647C-page 30 © 2009 Microchip Technology Inc.
ADVANCED OPTIONS
• Disable LED2 Default – Disable default LED2 behavior (LED2 = Yellow ‘Target’
LED)
• Disable LED1 Default – Disable default LED1 behavior (LED1 = Red ‘Busy’ LED)
• Enable Switch Test – Enable low-level switch test:
- Switch Off (not depressed) – blink LED1, LED2 off
- Switch ON (depressed) – blink LED2, LED1 off
• AUX1 Default State – AUX1 communication line – default state (0 | 1)
• AUX2 Default State – AUX2 communication line – default state (0 | 1)
• AUX1 Direction – AUX1 communication line – direction: 1: input, 0: output
• AUX2 Direction – AUX2 communication line – direction: 1: input, 0: output
4.6 COMMUNICATIONS: BASIC OPERATIONS
The I
2
C Basic Operations window can be opened by selecting:
• Communications: Basic Operations
from the tool bar, or
• Communications > Basic Operations
from the menu bar
The I
2
C Basic Operations window is shown in Figure 4-3. There are three basic
communications commands, Read and Write and Receive.
Read performs a combination Write then Read commands to the target device (refer to
the I
2
C Specification reference in Section 4.1 “Introduction” above). The basic
structure of the command is:
• Start bit (S_)
• Slave Address[W] – Enter the slave address of the device to communicate with.
The Write bit should be cleared to indicate a write operation.
• Word Address – Enter the word address
• Restart (RS),
• Slave Address[R] – The slave address with the Write bit set will be automatically
entered when the Slave Address[W] has been entered.
• Byte Count – Enter the number of bytes to be read
• Stop bit (P_)
Write performs a write operation to the target device (refer to The I
2
C Specification
reference in Section 4.1 “Introduction” above). The basic structure of the command
is:
• Start bit (S_)
• Slave Address[W] – Enter the slave address of the device to communicate with.
The Write bit should be cleared to indicate a write operation.
• Word Address – Enter the word address
• Data – Enter up to eight bytes of data
• Stop bit (P_)
The command will be logged in the Transactions window. A listing of the command
abbreviations is given in Table 4-2.
Note: The “x” indicates the value is a hexadecimal number. Clicking on “x” will
toggle it to a “d” indicating that the value is a decimal number.