9.4.3.1 ROM Mode 1

ROM mode 1 provides the quickest initialization from the TAS2555 initial power up and is the lowest power mode. This mode can be used to play a known power up audio sequence before the rest of the audio system software is loaded. The mode provides fault protection, brownout protection volume control, and class-H controller. With minimal additional configuration the EQ and Battery Guard can be enabled. The speaker protection algorithm is not running in this mode and the I/V sense ADC are powered down to minimize power consumption. The PLL can be disabled for even lower power consumption if the MCLK supplied is at least 12.288MHz for any fs which is multiple or sub-multiple of 48kHz, or 11.2896MHz for fs of 44.1kHz. This mode is set by writing B)_P0_R34[7:0]=0x21 before powering up the DSP B0_P0_R4[7]. This mode should be used to characterize the electrical performance on the TAS2555 device without any influence from the protection algorithm present in other modes.

Figure 36. ROM Mode 1 Processing Block Diagram