Table 19-6 Function Of Each Bit Of A/D Data Register (Adcr) - Fujitsu MB90420/5 (A) Series Hardware Manual

MB90420/5 (A) SERIES F

Table 19-6 Function of Each Bit of A/D Data Register (ADCR)

Bit Name
bit 15 S10:
A/D conversion
resolution select
bit
bit 14 ST1, ST0:
bit 13 Sampling time
setting bit
bit 12 CT1, CT0:
bit 11 Compare time
setting bit
bit 10 Empty bit
bit 9 D9 to D0:
to
bit 0
Notes: 1. Only rewrite the S10 bit when A/D conversion has not been performed yet and is currently
stopped. If the S10 bit is rewritten after the conversion, the value of the ADCR registers is
undefined.
2. When reading the ADCR registers with the 10-bit mode specified, always use the word transfer
instruction (such as MOVW A, 0022
2
MC-16LX FAMILY 16-BIT MICROCONTROLLERS HARDWARE MANUAL
• This bit selects the A/D conversion resolution.
• When 0 is written to this bit, 10-bit resolution is selected; when 1 is written, 8-bit
resolution is selected.
Note: The data bits used depend on the resolution.
• These bits select the sampling time used during A/D conversion.
• When A/D conversion is started, the time (analog input) set for these bits is input.
Note: When 00 (for 8 MHz) is set when 16 MHz is used, the normal analog voltage
may not be input.
• These bits select the compare time used during A/D conversion.
• The analog input is input (sampling time elapses), and then after the time set to
these bits elapses, data of conversion result is determined and stored in bits 9 to 0 of
this register.
Note: When 00 (for 8 MHz) is set when 16 MHz is used, the normal analog converted
value may not be obtained.
• The A/D conversion result is stored in this register; this register is rewritten each time
one conversion is terminated.
• Normally, the final converted value is stored in this register.
• The initial value of this register is undefined.
Note: A function to protect converted data is provided (see Section 16.6).
Do not write data to these bits during A/D conversion.
).
H
19-14
Function
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