at91sam9g20-cu ATMEL Corporation, at91sam9g20-cu Datasheet - Page 430

• Manufacturer Part Number: at91sam9g20-cu
• Description: At91 Arm Thumb Microcontrollers
• Manufacturer: ATMEL Corporation

430
AT91SAM9G20 Preliminary
Figure 31-20. TWI Read Operation with Multiple Data Bytes with or without Internal Address
No
Read Receive Holding register (TWI_RHR)
Read Receive Holding register (TWI_RHR)
(CLDIV, CHDIV, CKDIV) in TWI_CWGR
- Internal address size (if IADR used)
Set the Master Mode register:
TWI_CR = MSEN + SVDIS
Read ==> bit MREAD = 1
Internal address size = 0?
Set the Control register:
- Device slave address
- Transfer direction bit
Read Status register
Read Status register
Read status register
(Needed only once)
TWI_CR = START
TWI_CR = STOP
Yes
Last data to read
Start the transfer
Stop the transfer
- Master enable
TXCOMP = 1?
Set TWI clock
RXRDY = 1?
Yes
Yes
Yes
RXRDY = 1?
Yes
but one?
BEGIN
END
No
No
No
Set the internal address
TWI_IADR = address
6384B–ATARM–15-Dec-08