z16f2811 ZiLOG Semiconductor, z16f2811 Datasheet - Page 269

• Manufacturer Part Number: z16f2811
• Description: High Performance Microcontrollers
• Manufacturer: ZiLOG Semiconductor

Operation
PS022006-0207
Caution:
Flash Read Protection
Timing Using the Flash Frequency Register
FFREQ[15:0]
Flash programming and erasure is not supported for system clock frequencies be-
Table 134. ZNEO Z16F Series Information Area Map
The Flash Controller provides the proper signals and timing for Word programming, Page
Erase, and Mass erase of the flash memory. The Flash Controller contains a protection
mechanism, using the flash command register (FCMD), to prevent accidental
programming or erasure. The following subsections provide details on the various
operations (Lock, Unlock, Sector Protect, Byte Programming, Page Erase, and Mass
Erase).
Before performing a program or erase operation on the Flash memory, you must first
configure the Flash Frequency register. The Flash Frequency register allows programming
and erasure of the Flash with system clock frequencies ranging from 32 kHz through
20 MHz (the valid range is limited to the device operating frequencies).
The 16-bit Flash Frequency register must be written with the system clock frequency in
kHz before a program or erase operation is initiated. This value is calculated using the
following equation:
low 32 kHz, above 20 MHz, or outside of the device operating frequency range.
The Flash Frequency register must be loaded with the correct value to ensure prop-
er Flash programming and erase operations.
The user code within the Flash memory is protected from external access.
Programming the Flash Read Protect option bit prevents reading of user code by the
Program Memory Address (Hex)
000000H-00003FH
000040H-000053H
000054H-00007FH
=
System Clock Frequency (Hz)
--------------------------------------------------------------------------- -
P R E L I M I N A R Y
1000
Function
Reserved.
Part Number
20-character ASCII alphanumeric code
Left justified and padded with zeros.
Reserved.
Product Specification
ZNEO
™
Flash Memory
Z16F Series
255