ZLF645 MAXIM [Maxim Integrated Products], ZLF645 Datasheet - Page 87

• Manufacturer Part Number: ZLF645
• Description: Flash MCUs with Learning Amplification
• Manufacturer: MAXIM [Maxim Integrated Products]

Table 36. Flash Sector Protect Register (FSEC)
19-4572; Rev 0; 4/09
Bit Position
[7:0]
Bits
Field
Reset
R/W
Address
Caution:
Flash Frequency High and Low Byte Registers
SPROT7
R/W
7
0
The Flash Frequency High and Low Byte registers
form a 16-bit value, FFREQ, to control timing for Flash program and erase operations.
The 16-bit binary Flash frequency value must contain the system clock frequency (in kHz)
and is calculated using the following equation:
Programming the Flash Frequency High and Low Byte Registers as per the formula 
provides a Flash programming time of approximately 30 s and an erase time of 
approximately 10 ms.
Value
Flash programming and erasure is not supported for system clock frequencies below
1 MHz or above 8 MHz. The Flash Frequency High and Low Byte registers must be
loaded with the correct value to ensure proper operation of the device.
FFREQ[15:0]
SPROT6
R/W
6
0
Description
SPROT7-SPROT0 —Sector Protection
Each bit corresponds to an 16-page Flash sector. For the ZLF645xxxxx64, all
bits are used. Only bits 3-0 are used in the ZLF645xxxxx32. For ICP initiated
operations, no sector protection exists.
SPROT5
=
R/W
5
0

FFREQH[7:0], FFREQL[7:0]
Bank F, Register address 02H
SPROT4
R/W
4
0
SPROT3
R/W
3
0
(Table 37

SPROT2
=
R/W
ZLF645 Series Flash MCUs
System Clock Frequency (Hz)
------------------------------------------------------------------------------ -
2
0
Flash Control Register Definitions
and
Product Specification
SPROT1
Table
R/W
1000
0
1
38) combine to
SPROT0
R/W
0
0

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