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MB90420/5 (A) SERIES F
19.6.2 A/D-converted Data Protection Function
During A/D conversion with the interrupt enabled, the function to protect A/D-converted data operates.
n A/D-converted data protection function
This A/D converter has only one data register for storing converted data, so during A/D conversion, data
stored in the data register is rewritten at completion of conversion. Therefore, if previously converted data is
not transferred to memory before the current conversion is started, part of the previously converted data will
be lost. To prevent this, the data protection function operates when the interrupt is enabled (INTE = 1) as
explained below.
• Data protection function when EI
When converted data is stored in the A/D data register (ADCR), the INT bit of the A/D control status
register higher (ADCSH) is set to 1. While the INT bit is 1, the A/D conversion pauses. When the value of
the A/D data register (ADCR) is transferred to memory, etc., using the interrupt routine and then the INT bit
is cleared, the pause state is canceled.
• Data protection when EI
When the continuous conversion is specified using the EI
register upper (ADCSH) is set to 1 from the time the conversion is completed to transfer of converted data
in the data register to memory is completed using the EI
stopped and the next converted data is not stored. When transfer of data to memory is completed, the
PAUS bit is cleared to 0 and A/D conversion is resumed. Figure 19.11 shows the flow of the data
protection function when the EI
2
MC-16LX FAMILY 16-BIT MICROCONTROLLERS HARDWARE MANUAL
2
OS not used
2
OS used
2
OS is used.
2
OS, the PAUS bit of the A/D control status
2
OS. During this period, A/D conversion is
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