Datasheet

Data Sheet ADAS1000-3/ADAS1000-4
Rev. A | Page 55 of 76
Table 29. Respiration Control Register (RESPCTL) Address 0x03, Reset Value = 0x000000
1
R
/W
Default Bit Name Function
[23:17] Reserved
Reserved, set to 0.
R/W 0 16 RESPALTFREQ Setting this bit to 1 makes the respiration waveform on the GPIO3 pin periodic every cycle. Use in
conjunction with RESFREQ to select drive frequency.
0 (default) = periodic every N cycles (default).
1 = periodic every cycle.
R/W 0 15 RESPEXTSYNC Set this bit to 1 to drive the MSB of the respiration DAC out onto the GPIO3 pin. This signal can be
used to synchronize an external generator to the respiration carrier. It is a constant period only
when RESPALTFREQ = 1.
0 (default) = normal GPIO3 function.
1 = MSB of RESPDAC driven onto the GPIO3 pin.
R/W
0
14
RESPEXTAMP
For use with an external instrumentation amplifier with respiration circuit. Bypasses the on-chip
amplifier stage and input directly to the ADC. See Figure 65.
0 (default) = disabled.
1 = enabled.
R/W 0 13 RESPOUT Selects external respiration drive output. RESPDAC_RA is automatically selected when RESPCAP = 1
0 (default) = RESPDAC_LL and RESPDAC_RA.
1 = RESPDAC_LA and RESPDAC_RA.
R/W 0 12 RESPCAP Selects source of respiration capacitors.
0 (default) = use internal capacitors.
1 = use external capacitors.
R/W 0000 [11:8] RESPGAIN [3:0] Respiration in amp gain (saturates at 10).
0000 (default) = ×1 gain.
0001 = ×2 gain.
0010 = ×3 gain.
…
1000 = ×9 gain.
1001 = ×10 gain.
11xx = ×10 gain.
R/W 0 7 RESPEXTSEL Selects between EXT_RESP _LA or EXT_RESP_LL paths. Applies only if the external respiration is
selected in RESPSEL. EXT_RESP_RA is automatically enabled.
0 (default) = EXT_RESP_LL.
1 = EXT_RESP_LA.
R/W 00 [6:5] RESPSEL [1:0] Set leads for respiration measurement.
00 (default) = Lead I.
01 = Lead II.
10 = Lead III.
11 = external respiration path.
R/W 00 [4:3] RESPAMP Set the test tone amplitude for respiration drive signal.
00 (default) = amplitude/8.
01 = amplitude/4.
10 = amplitude/2.
11 = amplitude.
R/W 00 [2:1] RESPFREQ Set frequency for respiration.
RESPFREQ RESPALTFREQ = 0 RESPALTFREQ = 1 (periodic)
00 (default) 56 kHz 64 kHz
01 54 kHz 56.9 kHz
10 52 kHz 51.2 kHz
11 50 kHz 46.5 kHz
R/W 0 0 RESPEN Enable respiration.
0 (default) = respiration disabled.
1 = respiration enabled.
1
ADAS1000-4 model only, ADAS1000-3 model does not contain this feature.