 |
Motor de Búsqueda de Datasheet de Componentes Electrónicos |
|
|
Motor de Búsqueda de Datasheet de Componentes Electrónicos |
|
SH3000UM Datasheet(PDF) 13 Page - Semtech Corporation |
|
||||||||||||||||||||||||||||||
SH3000UM Datasheet(HTML) 13 Page - Semtech Corporation |
|
|
13 / 24 page  SH3000 MicroBuddy™ SYSTEM MANAGEMENT Copyright ©2003-2005 Semtech Corporation 13 V1.15 www.semtech.com Interrupt and Serial Interface A single line is used to convey bi-directional information between the SH3000 and the processor, and as the interrupt line to the processor. The polarity of the interrupt signal is programmable. The SH3000 and the host microcontroller communicate using a single wire, bi-directional asynchronous serial interface. The bit rate is automatically determined by the SH3000. . At the fastest possible rate, a read or write access of a single byte from the register bank takes 5 µs. The SH3000 contains 36 addressable registers located at 0x00–0x1F. Some of these registers are accessed through a page operation. Pin 14, IO/Int, is the serial communications interface and interrupt output pin. This pin is internally weakly pulled to the opposite of the programmed interrupt polarity. For example, if interrupt is programmed to be active low, this pin is weakly pulled to VDD when inactive. As shown in Figure 8, the SH3000 and the host communicate with serial data streams. The host always initiates communication. A data stream consists of the following (in this order): • 3-bit start field • 3-bit read/write code • 5-bit address field • 1 guard bit • 8-bit data field • 2 parity bits Plus, for write streams only: • 1 guard bit • 2 acknowledge (ACK) bits The 3-bit start field (1,0,1 or 0,1,0, depending on interrupt polarity) uses the middle bit to determine the bit period of the serial data stream. The 3-bit read/write code consists of 1,1,0 for a read, or 0,1,1 for a write. This protects against early glitches hat might otherwise put the interface into an invalid read or write access mode. The 5-bit address field contains the address of the register. A single guard bit gives the interface a safe period in which to change data direction. The value of a guard bit does not matter. The 8-bit data field is written to (read from) the register. Two parity bits: The first parity bit is high when there are an odd number of bits in the read/write, address and data fields; the second parity bit is the inverse of the first. For write streams only, a guard bit is appended to the stream (to allow safe turnaround), and then two acknowledge bits, which are a direct copy of the parity bits, are driven back to the host to indicate a successful write access. Two guard bits are appended to the end of the access stream (read or write). The host can not start the next access before receiving these bits. The interface is self-timed based on the duration of the start bit field, and communication can take place whenever CLKout is active, either at 32 kHz or at a higher frequency. If the host microcontroller is running synchronously to the CLKout generated by the SH3000 (which should generally be the case), then a minimum of 4 CLKout cycles per bit are required to maintain communication integrity. If the host’s serial interface is asynchronous to CLKout, then a minimum of 52 cycles per bit are necessary. A maximum of 1024 CLKout cycles per bit field is supported. Table 4 displays the minimum and maximum bit periods for the serial communications for CLKout frequencies of 16 MHz, 8 MHz, and 2 MHz. Table 4: Minimum/Maximum Serial Bit Timing CLKOUT Frequency Minimum Bit Period (host synchronous to CLKOUT) Minimum Bit Period (host asynchronous to CLKOUT) Maximum Bit Period 16 MHz 250 ns 3.25 µs 64 µs 8 MHz 500 ns 6.5 µs 128 µs 2 MHz 2 µs 26 µs 512 µs Interrupt Interface The serial communications line to the SH3000 (Pin 14, IO/Int) also serves as the interrupt to the host microcontroller. The polarity of the interrupt is software programmable using the interrupt polarity bit (bit 6) of the IPol_RCtune register (R0x11). This pin is asserted for four cycles of CLKout, and then returns to the inactive state. The interrupt line is used by the Periodic Interrupt/Wake-up Timer to interrupt the host when it reaches its end of count. |
Número de pieza similar - SH3000UM |
|
Descripción similar - SH3000UM |
|
|
|
Enlace URL |
| Política de Privacidad |
| ALLDATASHEET.ES |
| ¿ALLDATASHEET es útil para Ud.? [ DONATE ] |
Todo acerca de Alldatasheet | Publicidad | Contáctenos | Política de Privacidad | Intercambio de Enlaces | 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 |
Spanish ▼
English
Chinese
German
Japanese
Russian
Korean
Spanish
French
Italian
Portuguese
Polish
Vietnamese
Indian
Mexican
British
New Zealand
