cpu/avr/radio/rf230bb/rf230bb.c (rf230_transmit): extend comment on tx sequence

Explain that the transmission is intentionally started before copying the
frame to the buffer.
This commit is contained in:
Werner Almesberger 2013-07-09 10:41:17 -03:00
parent e13d69cf41
commit be0a296049

View File

@ -964,7 +964,9 @@ rf230_transmit(unsigned short payload_len)
/* No interrupts across frame download! */ /* No interrupts across frame download! */
HAL_ENTER_CRITICAL_REGION(); HAL_ENTER_CRITICAL_REGION();
/* Toggle the SLP_TR pin to initiate the frame transmission */ /* Toggle the SLP_TR pin to initiate the frame transmission, then transfer
* the frame. We have about 16 us + the on-air transmission time of 40 bits
* (for the synchronization header) before the transceiver sends the PHR. */
hal_set_slptr_high(); hal_set_slptr_high();
hal_set_slptr_low(); hal_set_slptr_low();
hal_frame_write(buffer, total_len); hal_frame_write(buffer, total_len);