EP7211 Datasheet, PDF (78/166 Pages) Cirrus Logic – HIGH-PERFORMANCE ULTRA-LOW-POWER SYSTEM-ON-CHIP WITH LCD CONTROLLER

EP7211
High-Performance Ultra-Low-Power System-on-Chip with LCD Controller
3.22 In-Circuit Emulation
3.22.1 Introduction
EmbeddedICE is an extension to the architecture of the ARM family of processors, and provides the
ability to debug cores that are deeply embedded into systems. It consists of three parts:
1) A set of extensions to the ARM core
2) The EmbeddedICE macrocell, to provide access the extensions from the outside world
3) The EmbeddedICE interface to provide communication from the EmbeddedICE macrocell and
the host computer
The EmbeddedICE macrocell is programmed, in a serial fashion, through the TAP controller on the
ARM via the JTAG interface. The EmbeddedICE macrocell is by default disabled to minimize power
usage, and must be enabled at boot-up to support this functionality.
3.22.2 Functionality
The ICEBreaker module consists of two real-time watchpoint units together with a control and status
register. One or both of the units can be programmed to halt the execution of the instructions by the
ARM processor. Execution is halted when either a match occurs between the values programmed
into the ICEBreaker and the values currently appearing on the address bus, data bus, and the various
control signals. Any bit can be masked to remove it from the comparison. Either unit can be
programmed as a watchpoint (monitoring data accesses) or a breakpoint (monitoring instruction
fetches).
Using one of these watchpoint units, an unlimited number of software breakpoints (in RAM) can be
supported by substitution of the actual code.
NOTE: The EXTERN[1:0] signals from the ICEBreaker module are not wired out in this device. This mecha-
nism is used to allow watchpoints to be dependent on an external event. This behavior can be emu-
lated in software via the ICEBreaker control registers.
A more detailed description is available in the ARM Software Development Toolkit User Guide
and Reference Manual. The ICEBreaker module and its registers are fully described in the
ARM7TDMI Datasheet, Chapters 8 and 9.
78
Functional Description
DS352PP3
JUL 2001