Z8F082ASH020SC Datasheet, PDF (175/244 Pages) Zilog, Inc. – Z8 Encore XP-R F08xA Series with eXtended Peripherals

Z8 Encore! XP^® F08xA Series
Product Specification
157
DBG ← 0DH
DBG ← Data Memory Address[15:8]
DBG ← Data Memory Address[7:0]
DBG ← Size[15:8]
DBG ← Size[7:0]
DBG → 1-65536 data bytes
• Read Program Memory CRC (0EH)—The Read Program Memory CRC command
computes and returns the Cyclic Redundancy Check (CRC) of Program Memory using the
16-bit CRC-CCITT polynomial. If the device is not in DEBUG mode, this command re-
turns FFFFH for the CRC value. Unlike most other OCD Read commands, there is a delay
from issuing of the command until the OCD returns the data. The OCD reads the Program
Memory, calculates the CRC value, and returns the result. The delay is a function of the
Program Memory size and is approximately equal to the system clock period multiplied
by the number of bytes in the Program Memory.
DBG ← 0EH
DBG → CRC[15:8]
DBG → 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 in-
structions 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 ← 11H
DBG ← opcode[7:0]
• Execute Instruction (12H)—The Execute Instruction command allows sending an en-
tire instruction to be executed to the eZ8 CPU. This command can also step over Break-
points. 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 ← 12H
DBG ← 1-5 byte opcode
PS024705-0405
PRELIMINARY
On-Chip Debugger