MC908AZ60ACFUER Datasheet, PDF (96/414 Pages) Freescale Semiconductor, Inc – To provide the most up-to-date information, the revision of our documents on the World Wide Web will be the most current. Your printed copy may be an earlier revision. To verify you have the latest information available, refer to:

EEPROM-2 Memory
EEDIVSECD — EEPROM-2 Divider Security Disable
This bit enables/disables the security feature of the EE2DIV registers. When EE2DIV security feature
is enabled, the state of the registers EE2DIVH and EE2DIVL are locked (including EEDIVSECD bit).
The EE2DIVHNVR and EE2DIVLNVR nonvolatile memory registers are also protected from being
erased/programmed.
1 = EE2DIV security feature disabled
0 = EE2DIV security feature enabled
EEDIV[10:0] — EEPROM-2 timebase prescaler
These prescaler bits store the value of EE2DIV which is used as the divisor to derive a timebase of
35μs from the selected reference clock source (CGMXCLK or bus block in the CONFIG-2 register) for
the EEPROM-2 related internal timer and circuits. EEDIV[10:0] bits are readable at any time. They are
writable when EELAT = 0 and EEDIVSECD = 1.
The EE2DIV value is calculated by the following formula:
EE2DIV= INT[Reference Frequency(Hz) x 35 x10^-6 +0.5]
Where the result inside the bracket is rounded down to the nearest integer value
For example, if the reference frequency is 4.9152MHz, the EE2DIV value is 172
NOTE
Programming/erasing the EEPROM with an improper EE2DIV value may
result in data lost and reduce endurance of the EEPROM device.
7.5.5 EEPROM-2 Timebase Divider Nonvolatile Register
The 16-bit EEPROM-2 timebase divider nonvolatile register consists of two 8-bit registers: EE2DIVHNVR
and EE2DIVLNVR. The contents of these two registers are respectively loaded into the EEPROM-2
timebase divider registers, EE2DIVH and EE2DIVL, after a reset.
These two registers are erased and programmed in the same way as an EEPROM-2 byte.
Address: $FF70
Bit 7
6
5
4
3
2
1
Bit 0
Read: _EEDIVS-
Write: ^ECD
R
R
R
R
EEDIV10 EEDIV9 EEDIV8
Reset:
Unaffected by reset; $FF when blank
R
= Reserved
Figure 7-7. EEPROM-2 Divider Nonvolatile Register High (EE2DIVHNVR))
Address: $FF71
Bit 7
6
5
4
3
2
1
Bit 0
Read:
EEDIV7
Write:
EEDIV6
EEDIV5
EEDIV4
EEDIV3 EEDIV2 EEDIV1 EEDIV0
Reset:
Unaffected by reset; $FF when blank
Figure 7-8. EEPROM-2 Divider Nonvolatile Register Low (EE2DIVLNVR)
MC68HC908AZ60A • MC68HC908AS60A • MC68HC908AS60E Data Sheet, Rev. 6
96
Freescale Semiconductor