AT89LP213 datasheet(64/90 Pages) ATMEL

64 / 90 page

3538A–MICRO–7/06

AT89LP213/214 [Preliminary]

22.2

Software Breakpoints

The AT89LP213/214 microcontroller includes a BREAK instruction for implementing program

memory breakpoints in software. A software breakpoint can be inserted manually by placing the

BREAK instruction in the program code. Some emulator systems may allow for automatic inser-

tion/deletion of software breakpoints. The Flash memory must be re-programmed each time a

software breakpoint is changed. Frequent insertions/deletions of software breakpoints will

reduce the data retention of the nonvolatile memory. Devices used for debugging purposes

should not be shipped to end customers. The BREAK instruction is treated as a two-cycle NOP

when OCD is disabled.

22.3

Limitations of On-chip Debug

The AT89LP213/214 is a low-cost, low-pincount yet fully-featured microcontroller that multi-

plexes several functions on its limited I/O pins. Some device functionality must be sacrificed to

provide resources for On-chip Debugging. The On-chip Debug System has the following

limitations:

• The Debug Clock pin (DCL) is physically located on that same pin as Port Pin P1.3 and the

External Reset (RST). Therefore, neither P1.3 nor an external reset source may be emulated

when OCD is enabled.

• The Debug Data pin (DDA) is physically located on either the XTAL1/P3.2 or XTAL2/P3.3 pin.

The crystal oscillator is therefore not supported during debug. The user must select either the

Internal RC Oscillator or the External Clock source to provide the system clock. Devices

fused for the crystal oscillator will default to external clock mode when OCD is enabled.

• When using the Internal RC Oscillator during debug, DDA is located on the XTAL1/P3.2 pin.

The INT0 function cannot be emulated in this mode.

• When using the External Clock during debug, DDA is located on the XTAL2/P3.3 pin and the

system clock drives XTAL1/P3.2. The INT0, INT1 and CLKOUT functions cannot be

emulated in this mode.

• The AT89LP213/214 does not support In-Application Programming and therefore the device

must be reset before changing the program code during debugging. This includes the

insertion/deletion of software breakpoints.

• When using the watchdog to generate a break, the state of the watchdog will not be reset. An

OCD reset command should be sent to the device prior to resuming normal execution to

ensure correct watchdog behavior.

AT89LP213 Datasheet(PDF) 64 Page - ATMEL Corporation