Z8F0830HH020SG Datasheet, PDF (166/257 Pages) Zilog, Inc. – High-Performance 8-Bit Microcontrollers

Z8 Encore!^® F0830 Series
Product Specification
148
ory size and is approximately equal to the system clock period multiplied by the number of
bytes in program memory.
DBG
DBG
DBG
←_{→ →}
0EH
CRC[15:8]
CRC[7:0]
Step Instruction (10H). The step instruction command, steps one assembly instruction at
the current program counter (PC) location. If the device is not in DEBUG Mode or the
Flash read protect option bit is enabled, the OCD ignores this command.
DBG ← 10H
Stuff Instruction (11H). The stuff instruction command, steps one assembly instruction
and allows specification of the first byte of the instruction. The remaining 0–4 bytes of the
instruction are read from program memory. This command is useful for stepping over
instructions where the first byte of the instruction has been overwritten by a breakpoint. If
the device is not in DEBUG Mode or the Flash read protect option bit is enabled, the OCD
ignores this command.
DBG
DBG
←
←
11H
opcode[7:0]
Execute Instruction (12H). The execute instruction command allows sending an entire
instruction to be executed to the eZ8 CPU. This command can also step over breakpoints.
The number of bytes to send for the instruction depends on the opcode. If the device is not
in DEBUG Mode or the Flash read protect option bit is enabled, this command reads and
discards one byte.
DBG
DBG
←
←
12H
1–5 byte
opcode
On-Chip Debugger Control Register Definitions
This section describes the features of the On-Chip Debugger Control and Status registers.
OCD Control Register
The OCD Control Register controls the state of the On-Chip Debugger. This register is
used to enter or exit DEBUG Mode and to enable the BRK instruction. It can also reset the
Z8 Encore! F0830 Series device.
A reset and stop function can be achieved by writing 81H to this register. A reset and go
function can be achieved by writing 41H to this register. If the device is in DEBUG Mode,
a run function can be implemented by writing 40H to this register.
PS025113-1212
On-Chip Debugger Control Register Definitions