ADM00419 Microchip Technology, ADM00419 Datasheet - Page 18

• Manufacturer Part Number: ADM00419
• Description: Power Management IC Development Tools MCP2210 Breakout Module
• Manufacturer: Microchip Technology
• Type: Other Power Managementr

Specifications of ADM00419

• Rohs: yes
• Product: Evaluation Kits
• Tool Is For Evaluation Of: MCP2210
• Input Voltage: 3.3 V, 5 V

MCP2210 Evaluation Kit User’s Guide
DS52057A-page 18
FIGURE 2-7:
When a system requires more than one SPI master sharing the same bus, an
arbitration scheme needs to be developed, to prevent multiple SPI masters trying to
access the bus at the same time. MCP2210 has support for such a mechanism, using
GP7 and GP8 (configured for dedicated pin functionality) for this purpose.
When GP8 is configured for its dedicated functionality, the pin can be used as a bus
release request for MCP2210 coming from another master. GP7 (configured for its ded-
icated functionality) is used as an SPI bus release acknowledge signal towards the
requesting master. When an external SPI master requests that the MCP2210 release
the bus, the MCP2210 completes the current SPI transfer (or it can be cancelled by the
PC application by sending the proper USB command). Then it releases the bus, and
signals this event on the acknowledge pin (GP7). The second master now has owner-
ship of the bus and can keep it as long as the SPI bus request pin (GP8) is kept
asserted.
In conclusion, when the dedicated functionality of the GP7 and GP8 are used,
MCP2210 can be used in a multiple SPI master system.
USB
MCP2210
MCP2210 TYPICAL USAGE DIAGRAM
USB-to-SPI
Interrupt
External
bridge
(GP6)
Chip-Select lines
SPI bus
SPI slave chip #1
Interrupt
© 2012 Microchip Technology Inc.
...
SPI slave chip #n
Interrupt
MOSI, MISO, SCK
CS0-CS8