MC908AZ32ACFUE Datasheet, PDF (52/324 Pages) Freescale Semiconductor, Inc – Microcontrollers

EEPROM
Addr. Register Name
Bit 7
6
5
4
3
2
1
Bit 0
$FE10
EEDIV Nonvolatile ^{Read: EEDIVS-}
Register High Write: ^ECD
R
(EEDIVHNVR)⁽¹⁾ _Reset:
R
R
R
EEDIV10 EEDIV9
Unaffected by reset; $FF when blank
EEDIV8
$FE11
EEDIV Nonvolatile ^Read:
Register Low Write:
(EEDIVLNVR)⁽¹⁾ _Reset:
EEDIV7
EEDIV6
EEDIV5 EEDIV4 EEDIV3 EEDIV2
Unaffected by reset; $FF when blank
EEDIV1
EEDIV0
EE Divider Register ^{Read: EEDIVS-}
0
$FE1A
High Write: ^ECD
(EEDIVH) _Reset:
0
0
0
EEDIV10 EEDIV9
Contents of EEDIVHNVR ($FE10), Bits [6:3] = 0
EEDIV8
$FE1B
EE Divider Register ^Read:
Low Write:
(EEDIVL) _Reset:
EEDIV7
EEDIV6
EEDIV5 EEDIV4 EEDIV3 EEDIV2
Contents of EEDIVLNVR ($FE11)
EEDIV1
EEDIV0
$FE1C
EEPROM Nonvolatile ^Read:
Register Write:
(EENVR)⁽¹⁾ _Reset:
UNUSED
UNUSED UNUSED EEPRTCT EEBP3 EEBP2 EEBP1
Unaffected by reset; $FF when blank; factory programmed $F0
EEBP0
$FE1D
Read:
0
EEPROM Control
Register (EECR)
Write:
UNUSED
Reset: 0
0
EEOFF
0
EERAS1 EERAS0
0
0
EELAT
0
AUTO
0
EEPGM
0
$FE1F
EEPROM Array ^Read:
Configuration Register Write:
(EEACR) _Reset:
UNUSED
UNUSED
UNUSED EEPRTCT EEBP3 EEBP2
Contents of EENVR ($FE1C)
EEBP1
EEBP0
1. Nonvolatile EEPROM register; write by programming.
= Unimplemented
R
= Reserved
UNUSED = Unused
Figure 5-1. EEPROM Register Summary
For EENVR, the corresponding volatile register is the EEPROM Array Configuration Register (EEACR).
For the EEDIVNCR (two 8-bit registers: EEDIVHNVR and EEDIVLNVR), the corresponding volatile
register is the EEPROM Divider Register (EEDIV: EEDIVH and EE DIVL).
5.4.2 EEPROM Timebase Requirements
A 35μs timebase is required by the EEPROM control circuit for program and erase of EEPROM content.
This timebase is derived from dividing the CGMXCLK or bus clock (selected by EEDIVCLK bit in
CONFIG-2 Register) using a timebase divider circuit controlled by the 16-bit EEPROM Timebase Divider
EEDIV Register (EEDIVH and EEDIVL).
As the CGMXCLK or bus clock is user selected, the EEPROM Timebase Divider Register must be
configured with the appropriate value to obtain the 35 μs. The timebase divider value is calculated by
using the following formula:
EEDIV= INT[Reference Frequency(Hz) x 35 x10^-6 +0.5]
This value is written to the EEPROM Timebase Divider Register (EEDIVH and EEDIVL) or programmed
into the EEPROM Timebase Divider Nonvolatile Register prior to any EEPROM program or erase
operations (see 5.4.1 EEPROM Configuration and 5.4.2 EEPROM Timebase Requirements).
MC68HC908AZ32A Data Sheet, Rev. 2
52
Freescale Semiconductor