DA6503.005
14 December 2016
OSCILLATOR FREQUENCY CONTROL REGISTER (E4/64HEX
)
Note that the internal clock oscillator frequency has
been factory trimmed and the trim value has been
stored in the EEPROM (DF/5FHEX). It is
recommended not to change the factory
programmed value!
The six LSB bits adjust the oscillator signal period
in 65ns steps. The signal period decreases and
frequency increases when the trim value increases.
The six bit register value is considered as a 2’s
complement number. Typically a mid value 00HEX
corresponds to the nominal 500 kHz clock oscillator
frequency.
The oscillator frequency control register (E4/64HEX
)
is for trimming the internal clock oscillator to 500
kHz frequency. When settings FOSC=1 in the Test
register (E1/61HEX) the 500 kHz clock signal can be
measured at the OSC pin.
After finding a suitable trim value it can be stored to
the EEPROM (DF/5FHEX).
Table 5. Oscillator frequency control register (E6/66HEX
)
Bit
Number
Bit Name Description
Value
(bin)
Value
(2’s
Value
(dec)
Function
complement)
7-6
5-0
-
Not used
Oscillator
frequency
control
X
X
31
30
…
1
0
-1
-2
X
31
30
…
1
-
OSCF
011111
011110
…….
000001
000000
111111
111110
…….
Max frequency
…
…
…
0
Nominal 500 kHz
63
62
…
33
32
…
…
…
…
…
-31
-32
100001
100000
Min frequency
X = Don’t care
EEPROM DATA INPUT REGISTER (E5/65HEX
)
This register can be ignored by user. It is related to
internal EEPROM operations and updated
automatically during every EEPROM write
operation.
EEPROM WRITE ENABLE REGISTER (E6/66HEX
)
The EEPROM is normally write protected. To
enable write the EEPROM write enable register
should be set to %00000100 (04HEX). To disable
write the register should be set to %00000000
(00HEX) which is the register default value after
power-on-reset or manual reset by XCLR or by
reset register. Note: don’t use any other EEPROM
write enable register values than these two since
other register bits are reserved for internal testing
purpose only.
Table 6. EEPROM write enable register (E9/69HEX
)
Bit Number
Bit Name
Description
Value
Function
7-3
00000
Reserved. Keep these bits
always 0.
2
EWE
EEPROM write enable
0
1
00
EEPROM write disabled
EEPROM write enabled
Reserved. Keep these bits
always 0.
1-0
17 (34)
MAS [ MICRO ANALOG SYSTEMS ]
