Atmel ARM-Based Evaluation Kit AT91SAM9N12-EK AT91SAM9N12-EK Data Sheet
Product codes
AT91SAM9N12-EK
798
SAM9N12/SAM9CN11/SAM9CN12 [DATASHEET]
11063K–ATARM–05-Nov-13
Figure 40-52. Master Node with DMAC (PDCM = 0)
Slave Node Configuration
In this configuration, the DMAC transfers only the DATA. The Identifier must be read by the user in the LIN Identifier
register (US_LINIR). The LIN mode must be written by the user in the LIN Mode register (US_LINMR).
register (US_LINIR). The LIN mode must be written by the user in the LIN Mode register (US_LINMR).
The WRITE buffer contains the DATA if the USART sends the response (NACT = PUBLISH).
The READ buffer contains the DATA if the USART receives the response (NACT = SUBSCRIBE).
Figure 40-53. Slave Node with DMAC
40.7.8.17 Wake-up Request
Any node in a sleeping LIN cluster may request a wake-up.
In the LIN 2.0 specification, the wakeup request is issued by forcing the bus to the dominant state from 250 µs to 5 ms.
For this, it is necessary to send the character 0xF0 in order to impose 5 successive dominant bits. Whatever the baud
rate is, this character respects the specified timings.
For this, it is necessary to send the character 0xF0 in order to impose 5 successive dominant bits. Whatever the baud
rate is, this character respects the specified timings.
Baud rate min = 1 Kb/s -> Tbit = 1 ms -> 5 Tbits = 5 ms
Baud rate max = 20 Kb/s -> Tbit = 50 µs -> 5 Tbits = 250 µs
In the LIN 1.3 specification, the wakeup request should be generated with the character 0x80 in order to impose eight
successive dominant bits.
successive dominant bits.
The user can choose by the WKUPTYP bit in the LIN Mode register (US_LINMR) either to send a LIN 2.0 wakeup
request (WKUPTYP = 0) or to send a LIN 1.3 wakeup request (WKUPTYP = 1).
request (WKUPTYP = 0) or to send a LIN 1.3 wakeup request (WKUPTYP = 1).
A wake-up request is transmitted by writing the Control Register (US_CR) with the LINWKUP bit to 1. Once the transfer
is completed, the LINTC flag is asserted in the Status Register (US_SR). It is cleared by writing the US_CR with the
RSTSTA bit to 1.
is completed, the LINTC flag is asserted in the Status Register (US_SR). It is cleared by writing the US_CR with the
RSTSTA bit to 1.
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RXRDY
TXRDY
TXRDY
APB bus
USART3
LIN CONTROLLER
DATA 0
DATA N
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WRITE BUFFER
USART3
LIN CONTROLLER
READ BUFFER
NODE ACTION = PUBLISH
NODE ACTION = SUBSCRIBE
APB bus
IDENTIFIER
DATA 0
DATA N
WRITE BUFFER
IDENTIFIER
(Peripheral) DMA
Controller
(Peripheral) DMA
Controller
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DATA 0
DATA N
RXRDY
USART3
LIN CONTROLLER
APB bus
READ BUFFER
NACT = SUBSCRIBE
DATA 0
DATA N
TXRDY
USART3
LIN CONTROLLER
APB bus
WRITE BUFFER
(Peripheral) DMA
Controller
(Peripheral) DMA
Controller