Z8F082ASH020SC Datasheet, PDF (171/244 Pages) Zilog, Inc. – Z8 Encore XP-R F08xA Series with eXtended Peripherals

Z8 Encore! XP^® F08xA Series
Product Specification
153
Runtime Counter
The On-Chip Debugger contains a 16-bit Runtime Counter. It counts system clock cycles
between Breakpoints. The counter starts counting when the On-Chip Debugger leaves
DEBUG mode and stops counting when it enters DEBUG mode again or when it reaches
the maximum count of FFFFH.
On-Chip Debugger Commands
The host communicates to the On-Chip Debugger by sending OCD commands using the
DBG interface. During normal operation, only a subset of the OCD commands are avail-
able. In DEBUG mode, all OCD commands become available unless the user code and
control registers are protected by programming the Flash Read Protect Option bit (FRP).
The Flash Read Protect Option bit prevents the code in memory from being read out of the
Z8 Encore! XP^® F08xA Series products. When this option is enabled, several of the OCD
commands are disabled. Table 99 on page 158 is a summary of the On-Chip Debugger
commands. Each OCD command is described in further detail in the bulleted list follow-
ing this table. Table 99 also indicates those commands that operate when the device is not
in DEBUG mode (normal operation) and those commands that are disabled by program-
ming the Flash Read Protect Option bit.
Debug Command
Read OCD Revision
Reserved
Read OCD Status Register
Read Runtime Counter
Write OCD Control Register
Read OCD Control Register
Write Program Counter
Read Program Counter
Write Register
Read Register
Write Program Memory
Read Program Memory
Command Enabled when NOT
Byte
in DEBUG mode?
Disabled by
Flash Read Protect Option Bit
00H
Yes
–
01H
–
–
02H
Yes
–
03H
–
–
04H
Yes
Cannot clear DBGMODE bit
05H
Yes
–
06H
–
Disabled
07H
–
Disabled
08H
–
Only writes of the Flash Memory Control
registers are allowed. Additionally, only
the Mass Erase command is allowed to
be written to the Flash Control register.
09H
–
Disabled
0AH
–
Disabled
0BH
–
Disabled
PS024705-0405
PRELIMINARY
On-Chip Debugger