SPRUJ55D September 2023 – July 2025 AM263P2 , AM263P2-Q1 , AM263P4 , AM263P4-Q1
This diagnostic check monitors the demodulated Sine and Cosine input signals to RDC, after offset correction and demodulation, but before phase and gain correction. For good set of input signals, the amplitude of either of the demodulated Sine and Cosine signals should be above above a threshold. If neither of the signals are above the threshold set by lowamplitude_threshold, it causes the glitch counter to increase by one. Once the glitch counter reaches the threshold programmed in lowamplitude_glitchcount, it causes an error. This diagnostic check does not need the external Resolver to be rotating.
The value in lowamplitude_threshold determines the threshold for this error. Since the full scale amplitude value of input signals with gain 1 would be 215, a typical value between 213 = 8192 to 212 = 4096 can be programmed as lowamplitude_threshold. While programming the lowamplitude_threshold, care has to be taken to ensure it accomodates the Sine and Cosine signal values when they are equal (example when external Resolver connected to RDC is at 45 Degrees).
The below Table 7-147 shows the relevant diagnostics registers for both RDC0 and RDC1.| RDC Instance | Register Name | Physical Address | Offset |
|---|---|---|---|
| RDC0 | DIAG5_0 | 502C B0A8h | 0A8h |
| DIAG6_0 | 502C B0ACh | 0ACh | |
| RDC1 | DIAG5_1 | 502C B278h | 278h |
| DIAG6_1 | 502C B27Ch | 27Ch |
The below Table 7-148 shows the corresponding bits to be programmed in the diagnostics registers.
| Register | Bit | Field | Type | Reset | Typical Programmed Value | Description |
|---|---|---|---|---|---|---|
| DIAG5_0 DIAG5_1 |
23:16 | lowamplitude_glitchcount | R/W | 0x1 | - | Low Amplitude Error counter limit for issuing error |
| 15:0 | lowamplitude_threshold | R/W | 0x0 | 8192 | Threshold value to detect Low Amplitude value. Both Sine and Cosine need to be lower than this. | |
| DIAG6_0 DIAG6_1 |
31:16 | lowamplitude_cos | R | x | - | Value of Cosine Signal at the low amplitude error trigger instant |
| 15:0 | lowamplitude_sin | R | x | - | Value of Sine Signal at the low amplitude error trigger instant |
The below Table 7-149 shows the register bit of IRQ registers to be used for Reading Status, Enabling/Disabling this Diagnostic check.
| Bit | Field | Type | Reset | Description |
|---|---|---|---|---|
| 0 | lowamplitude_err | rw1ts | 0x0 | Demodulated Sine and Cosine signals not crossing low amplitude Threshold |
The below are the typical steps for programming this check.
IRQSTATUS_SYS_x
Associated AM263Px MCU+ SDK API with this check: Diag_Mon_Sin_Cos_Weak_Amplitude