Os motores de busca de Datasheet de Componentes eletrônicos |
|
SI4840 Folha de dados(PDF) 9 Page - Silicon Laboratories |
|
SI4840 Folha de dados(HTML) 9 Page - Silicon Laboratories |
9 / 71 page AN610 Rev. 0.3 9 5.1.3. Power Off Sequence 1. System controller can optionally issue the POWER_DOWN command first to stop device current operations. 2. System controller holds the ATDD device RSTb pin in low state in power off. The current consumption of the ATDD device will be at about 10 µA at 3.3 V supply. (Note that the Si47xx DTDD device POWER_UP commands is not supported in the ATDD device; the system controller needs to reset device and issue ATDD_POWER_UP command to power up.) 5.2. Band Detection by System Controller Figure 5. Band Detection and Control by System Controller The system controller is responsible for detecting the band with its own mechanism. The method used to handle band switching on the ATDD device depends on whether the system controller wants to switch to the new band within the same band mode (e.g., FM1 FM5) or switch it across different band modes (e.g. FM5AM1).For example, to switch to a new band within the same band mode, the system controller should re-issue the power up command with the new band number, optionally with band properties other than the predefined ones. Alternatively, to switch across different band modes, the system controller should reset the ATDD device and wait till it is ready again, then issue the same power up command with the new band number with optional band properties. 5.2.1. Power On Sequence 1. System controller resets the ATDD device and releases the RSTb pin. 2. System controller waits till first IRQ is received (indicates that the ATDD device is ready to receive commands). 3. System controller issues ATDD_GET_STATUS command to obtain the ATDD device status. The system controller is required to check in the reply from the BCFG0 bit to determine if the ATDD device or the system controller is responsible for band detection and selection. In this case, the BCFG0 bit should be 1 (i.e., host detects band). Note that the HOSTPWRUP bit is always set, which prompts the system controller to issue the ATDD_POWER_UP command. Band and tune information are not ready in this power up stage. 4. System controller issues ATDD_POWER_UP command with the bulleted arguments below to power up the device: Set ARG1 bit[5:0] BANDIDX band index to the desired band number. Set ARG1 bit[7] XOSEN bit = 1 if a 32.768 kHz crystal is in use. Set ARG1 bit[6] XOWAIT bit =0 if typical 600 ms crystallization time is enough or set the XOWAIT bit = 1 for a longer time of 900 ms. Optionally include ARG2 ARG3* if new band bottom frequency is different from default. Optionally include ARG4 ARG5* if new band top frequency is different from default. Optionally include ARG6* if new band channel space is different from default (AM only). Optionally include ARG7 for new features of Si4827 and Si4844B devices. 5. System controller waits till IRQ is received for the tune wheel frequency ready. 6. System controller issues ATDD_GET_STATUS command to obtain the latest status for display: If REPLY0 bit[4] INFORDY bit = 1, i.e., info ready, the host can read and display the status, such as the band mode, the station, and stereo states. The tune frequency is ready when combined frequency of REPLY2, REPLY3 is non-zero (4-digit BCD number). 7. Optionally, the system controller can issue the ATDD_AUDIO_MODE command to specify the number of Host MCU (Master) ATDD Tuner (Slave) RSTb IRQ SCLK SDIO PVR Tune wheel FM AM Band select VDD1 |
Nº de peça semelhante - SI4840 |
|
Descrição semelhante - SI4840 |
|
|
Ligação URL |
Privacy Policy |
ALLDATASHEETPT.COM |
ALLDATASHEET é útil para você? [ DONATE ] |
Sobre Alldatasheet | Publicidade | Contato conosco | Privacy Policy | roca de Link | Lista de Fabricantes All Rights Reserved©Alldatasheet.com |
Russian : Alldatasheetru.com | Korean : Alldatasheet.co.kr | Spanish : Alldatasheet.es | French : Alldatasheet.fr | Italian : Alldatasheetit.com Portuguese : Alldatasheetpt.com | Polish : Alldatasheet.pl | Vietnamese : Alldatasheet.vn Indian : Alldatasheet.in | Mexican : Alldatasheet.com.mx | British : Alldatasheet.co.uk | New Zealand : Alldatasheet.co.nz |
Family Site : ic2ic.com |
icmetro.com |