mc9s12xd256 Freescale Semiconductor, Inc, mc9s12xd256 Datasheet - Page 1154

• Manufacturer Part Number: mc9s12xd256
• Description: Hcs12x Microcontrollers
• Manufacturer: Freescale Semiconductor, Inc

Chapter 28 256 Kbyte Flash Module (S12XFTX256K2V1)
28.3.2.1
The FCLKDIV register is used to control timed events in program and erase algorithms.
All bits in the FCLKDIV register are readable, bits 6-0 are write once and bit 7 is not writable.
28.3.2.2
The FSEC register holds all bits associated with the security of the MCU and Flash module.
1154
RESERVED1
RESERVED2
RESERVED3
RESERVED4
FDIV[5:0]
PRDIV8
FDIVLD
Register
Reset
Field
Name
5:0
7
6
W
R
FDIVLD
Clock Divider Loaded.
0 Register has not been written.
1 Register has been written to since the last reset.
Enable Prescalar by 8
0 The oscillator clock is directly fed into the clock divider
1 The oscillator clock is divided by 8 before feeding into the clock divider.
Clock Divider Bits — The combination of PRDIV8 and FDIV[5:0] must divide the oscillator clock down to a
frequency of 150 kHz–200 kHz. The maximum divide ratio is 512. Please refer to
FCLKDIV Register”
Flash Clock Divider Register (FCLKDIV)
Flash Security Register (FSEC)
0
7
W
W
W
W
R
R
R
R
Bit 7
= Unimplemented or Reserved
0
0
0
0
PRDIV8
Figure 28-3. FTX256K2 Register Summary (continued)
0
6
Figure 28-4. Flash Clock Divider Register (FCLKDIV)
for more information.
.
6
0
0
0
0
Table 28-2. FCLKDIV Field Descriptions
MC9S12XDP512 Data Sheet, Rev. 2.17
FDIV5
0
5
5
0
0
0
0
FDIV4
0
4
Description
4
0
0
0
0
.
FDIV3
0
3
3
0
0
0
0
FDIV2
0
2
2
0
0
0
0
Section 28.4.1.1, “Writing the
Freescale Semiconductor
FDIV1
0
1
1
0
0
0
0
FDIV0
Bit 0
0
0
0
0
0
0