HAL-APB-V1.5 Datasheet, PDF (28/59 Pages) Micronas – Application Board HAL-APB V1.x

HAL1820, HAL24xy, HAL28xy, HAL36xy, HAL38xy
Application Board HAL-APB V1.x
APPLICATION NOTE
8.4.4. Data check
To allow data transmission in rough environments, two separate check mechanisms are
implemented.
The command bits and the address bits are followed by a common parity bit as per
description
8.4.5. CRC
The data bits are always followed by 4 CRC bits. For all commands but read the CRC
result is calculated of all protocol bits, including command, address, parity and data
bits.
For read command, the CRC result is calculated of dummy bit and data bits only (16).
The polynomial for the CRC calculation is always X⁴+X+1.
In case of correct command detection (parity, CRC and command address if applica-
ble), ACK is sent.
Disrupted transfers can be retried by the master.
8.4.6. Parity check
For the command and address bits, an “odd” parity check is used. In the case of an
even number of “1”s, the parity bit has to be “1”. In the case of on odd number of “1”s,
the parity bit has to be “0”. With the parity bit, global parity is always even.
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Oct. 8, 2012; APN000055_003EN
Micronas