s908az32ag2cfue Freescale Semiconductor, Inc, s908az32ag2cfue Datasheet - Page 52

• Manufacturer Part Number: s908az32ag2cfue
• Description: M68hc08 Microcontrollers 8-bit Microcontroller
• Manufacturer: Freescale Semiconductor, Inc

EEPROM
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:
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
52
1. Nonvolatile EEPROM register; write by programming.
$FE1A
$FE1B
$FE1C
$FE1D
$FE1F
$FE10
$FE11
Addr.
EEDIV= INT[Reference Frequency(Hz) x 35 x10
Configuration Register
EEPROM Nonvolatile
Register Name
EE Divider Register
EE Divider Register
EEDIV Nonvolatile
EEDIV Nonvolatile
EEPROM Control
(EEDIVHNVR)
Register (EECR)
(EEDIVLNVR)
EEPROM Array
Register High
Register Low
(EENVR)
5.4.1 EEPROM Configuration
(EEDIVH)
(EEDIVL)
(EEACR)
Register
High
Low
(1)
(1)
(1)
Reset:
Reset:
Reset:
Reset:
Reset:
Reset:
Reset:
Read:
Read:
Read:
Read:
Read:
Read:
Read: UNUSED
Write:
Write:
Write:
Write:
Write:
Write:
Write:
Figure 5-1. EEPROM Register Summary
UNUSED
UNUSED
EEDIVS-
EEDIVS-
EEDIV7
EEDIV7
Bit 7
ECD
ECD
0
MC68HC908AZ32A Data Sheet, Rev. 2
= Unimplemented
UNUSED
UNUSED
EEDIV6
EEDIV6
R
6
0
0
0
Unaffected by reset; $FF when blank; factory programmed $F0
and
UNUSED
UNUSED
EEDIV5
EEDIV5
EEOFF
Contents of EEDIVHNVR ($FE10), Bits [6:3] = 0
5.4.2 EEPROM Timebase
-6
R
5
0
0
+0.5]
Unaffected by reset; $FF when blank
Unaffected by reset; $FF when blank
Contents of EEDIVLNVR ($FE11)
Contents of EENVR ($FE1C)
EEPRTCT
EEPRTCT
EERAS1
EEDIV4
EEDIV4
R
R
4
0
0
= Reserved
EERAS0
EEDIV3
EEDIV3
EEBP3
EEBP3
R
3
0
0
Requirements).
EEDIV10
EEDIV10
EEDIV2
EEDIV2
EEBP2
EEBP2
EELAT
2
0
Freescale Semiconductor
UNUSED
EEDIV9
EEDIV1
EEDIV9
EEDIV1
EEBP1
EEBP1
AUTO
1
0
= Unused
EEDIV8
EEDIV0
EEDIV8
EEDIV0
EEPGM
EEBP0
EEBP0
Bit 0
0