UM10147_2
© NXP B.V. 2008. All rights reserved.
User manual
Rev. 02 — 28 April 2008
28 of 134
NXP Semiconductors
UM10147
P89LPC952/954 User manual
conversions. Additional conversion results will again cycle through the result register
pairs, overwriting the previous results. Continuous conversions continue until terminated
by the user. This mode is selected by setting the SCC0 bit in the ADMODA register.
3.2.1.3
Auto scan, single conversion mode
Any combination of the eight input channels can be selected for conversion by setting a
channel’s respective bit in the ADINS register. A single conversion of each selected input
will be performed and the result placed in the result register pair which corresponds to the
selected input channel (see
). The user may select whether an interrupt, if
enabled, will be generated after either the first four conversions have occurred or all
selected channels have been converted. If the user selects to generate an interrupt after
the first four input channels have been converted, a second interrupt will be generated
after the remaining input channels have been converted. If only a single channel is
selected this is equivalent to single channel, single conversion mode. The channels are
converted from LSB to MSB order (in ADINS). This mode is selected by setting the
SCAN0 bit in the ADMODA register.
3.2.1.4
Auto scan, continuous conversion mode
Any combination of the eight input channels can be selected for conversion by setting a
channel’s respective bit in the ADINS register. A conversion of each selected input will be
performed and the result placed in the result register pair which corresponds to the
selected input channel (See
). The user may select whether an interrupt, if
enabled, will be generated after either the first four conversions have occurred or all
selected channels have been converted. If the user selects to generate an interrupt after
the four input channels have been converted, a second interrupt will be generated after
the remaining input channels have been converted. After all selected channels have been
converted, the process will repeat starting with the first selected channel. Additional
conversion results will again cycle through the eight result register pairs, overwriting the
previous results. Continuous conversions continue until terminated by the user. The
channels are converted from LSB to MSB order (in ADINS). This mode is selected by
setting the BURST0 bit in the ADMODA register.
3.2.1.5
Dual channel, continuous conversion mode
This is a variation of the auto scan continuous conversion mode where conversion occurs
on two user-selectable inputs. Any combination of two of the eight input channels can be
selected for conversion. The result of the conversion of the first channel is placed in the
result register pair, AD0DAT0R and AD0DAT0L. The result of the conversion of the
Table 8.
Result registers and conversion results for fixed channel, continuous conversion
mode
Result register
Contains
AD0DAT0R/L
Selected channel, first conversion result
AD0DAT1R/L
Selected channel, second conversion result
AD0DAT2R/L
Selected channel, third conversion result
AD0DAT3R/L
Selected channel, fourth conversion result
AD0DAT4R/L
Selected channel, fifth conversion result
AD0DAT5R/L
Selected channel, sixth conversion result
AD0DAT6R/L
Selected channel, seventh conversion result
AD0DAT7R/L
Selected channel, eighth conversion result