bp (Breakpoint)

bp[number]addr [count] ["cmds"]
 

The bp command creates a software breakpoint at an address. When the application is running, software breakpoints stop execution and force the debugger to execute the default or optional command string. Unlike breakpoints created by the g command, software breakpoints remain in memory until you remove them with the bc command or temporarily disable them with the bd command.

number
Specifies which breakpoint is being created. No space is allowed between the bp and number. If number is omitted, the first available breakpoint number is used. The debugger allows up to 10 software breakpoints (0 through 9). If you specify more than 10 breakpoints, the debugger returns the message: "Too Many Breakpoints."
addr
Specifies any valid instruction address — the first byte of an operation code (opcode). The addr parameter is required for all new breakpoints.
count
Specifies the number of times the breakpoint is to be ignored before being executed. It can be any 16-bit value.
cmds
Specifies an optional list of debugger commands to be executed in place of the default command when the breakpoint is reached. You must enclose optional commands in quotation marks and separate optional commands with semicolons (;).

This example creates a breakpoint at address CS:401000:

bp 401000

This example creates breakpoint 8 at address given by the symbol _MyTest. When the breakpoint occurs, the debugger displays bytes at DS:SI:

bp8 _MyTest "db DS:SI"