A N 9 3
302
Rev. 1.4
A
PPENDIX
C—P
ARALLEL
/SPI I
NTERFACE
S
OFTWARE
I
MPLEMENTATION
This appendix describes the software interface requirements for communication with the ISOmodem in parallel or
SPI mode. Figure 75 shows a typical connection between a PC and the modem using the MCU C8051F12x as
interface:
Figure 75. PC to Modem Connection through a C8051F12x Demo Board
A typical application is structured in four software layers:
1. Hardware access: where the MCU performs all the basic I/O accesses to and from the modem
2. Interrupt service or polling: depending on the mode of access (polling or interrupt), this layer contains the
algorithms that determine when the host and the modem exchange data.
3. Data buffer management, status and control: this portion of the code relays data between the UART and the
modem in both directions. Access functions to set the software interrupt mask and the escape bit, and to query
the status of software interrupts. The implementation of this layer depends on the requirements of the
application layer.
4. The application layer: this code depends on the application.
Содержание Si2404
Страница 2: ...AN93 2 Rev 1 4 ...
Страница 27: ...AN93 Rev 1 4 27 Figure 7 Parallel Interface Read Timing Figure 8 Parallel Interface Write Timing ...
Страница 200: ...AN93 200 Rev 1 4 Figure 31 TAM Handset and Speakerphone Voice Paths ...
Страница 201: ...AN93 Rev 1 4 201 Figure 32 Si3000 Codec Gain and Signal Selection Options ...
Страница 290: ...AN93 290 Rev 1 4 Figure 57 256 Band Spectral Display Figure 58 2048 Band Spectral Display ...
Страница 305: ...AN93 Rev 1 4 305 Figure 76 Parallel or SPI Port Interrupt Service Flowchart ...