3
Z89C6501ZEM
CP96TAD00403
LIMITATIONS
1. Breakpointing in interrupt service routine and single-
stepping pass the IRET statement will cause global
interrupts to be disabled.
2. Do not put breakpoint at address after Stop instruction.
This will cause program counter to continue at that
location after a Stop-Mode Recovery.
3. The C65 ICEBOX uses the Z86C50 ICE Chip; therefore,
emulation at more than 12 MHz requires that the
Expanded Register File (ERF) timing of the ICE Chip
be slowed down to SCLK x 2. This is accomplished by
loading value %01 to ICECON Register (Bank F,
Register A) of the ICE Chip.
Example:
PUSH RP
LD RP, #%0F
LD %A, #%01
POP RP
4. Changing drives in file download and load symbol
dialog boxes is not anticipated by the GUI. Typing in
the filename in a directory other than shown in “Path:”
will result in “File not found”. Changing the drive using
the mouse is the workaround.
5. The initial blue Zilog screen will be distorted by other
active windows. This only affects the appearance, not
functionality, of the GUI.
6. Switching ICEBOXes without quitting the GUI is not
supported.
7. The maximum symbols that can be loaded is 32768,
provided that there is enough system resource
(memory).
8. The ICEBOX breakpoint hardware does not distinguish
between instruction and data fetches. When a
breakpoint in the GUI is set, the breakpoint hardware
triggers when the addresses match for either code or
data fetches.
Example:
000C SRP #%0
000E LD R4, #%0016
0010 LD R5, @R4
0012 NOP
0013 JP %000C
0016 NOP
Setting the breakpoint at %0016 and click GO.
Result: The code will break and stop at %0012.
Note: This will not happen when Animate Mode is on
because the GUI is not using the hardware breakpoints
when in Animate Mode.
9. Clicking on the HALT Button does not always Halt
ICEBOX execution.
10. Single-stepping into the HALT instruction will cause an
ICEBOX "Fatal Error".
11. Halting the program execution or breakpointing when
interrupts are enabled will globally disable interrupts.
If halting occurs, the program must be reset and
started from address %000c hex.
12. Due to the limitation in the Z86C50 ICE Chip, a software
work around for the interrupt vector fetching must be
in place when configuring the emulator for ROMless
emulation (Z89C66/166 emulation).
13. If the emulator is running a user code at full speed and
the port window is opened: Switching to another
application or minimizing the GUI (then restoring) will
result in the following ICEBOX Communications Error
message: “Emulator rejected command: target
program is executing.” This message may need to be
cleared several times (as many as seven) before the
GUI returns to normal operation.
Workaround: Always close the port window before
leaving the GUI.
