Z8F0830HH020SG Datasheet, PDF (162/257 Pages) Zilog, Inc. – High-Performance 8-Bit Microcontrollers

Z8 Encore!^® F0830 Series
Product Specification
144
Runtime Counter
The OCD contains a 16-bit runtime counter. It counts system clock cycles between break-
points. The counter starts counting when the OCD leaves DEBUG Mode and stops count-
ing 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 FRP prevents the code in memory from being read out of the Z8 Encore! F0830 Series
products. When this option is enabled, several of the OCD commands are disabled.
Table 95 summarizes the On-Chip Debugger commands. This table indicates the com-
mands that operate when the device is not in DEBUG Mode (normal operation) and the
commands that are disabled by programming the FRP.
Table 95. On-Chip Debugger Command Summary
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
Write Data Memory
Read Data Memory
Command
Byte
00H
01H
02H
03H
04H
05H
06H
07H
08H
09H
0AH
0BH
0CH
0DH
Enabled when not
in DEBUG Mode?
Yes
–
Yes
–
Yes
Yes
–
–
–
–
–
–
–
–
Disabled by
Flash Read Protect Option Bit
–
–
–
–
Cannot clear DBGMODE bit
–
Disabled
Disabled
Only writes of the Flash Memory Con-
trol registers are allowed. Additionally,
only the Mass Erase command is
allowed to be written to the Flash Con-
trol register.
Disabled
Disabled
Disabled
Yes
–
PS025113-1212
On-Chip Debugger Commands