57.7.8.13 Frame Slot Mode

This mode is useful only for host nodes. It respects the following rule: each frame slot shall be longer than or equal to t_{Frame_Maximum}.

If the Frame Slot mode is enabled (FSDIS = 0) and a frame transfer has been completed, the TXRDY flag is set again only after t_{Frame_Maximum} delay, from the start of frame. So the host node cannot send a new header if the frame slot duration of the previous frame is inferior to t_{Frame_Maximum}.

If the Frame Slot mode is disabled (FSDIS = 1) and a frame transfer has been completed, the TXRDY flag is set again immediately.

The t_{Frame_Maximum} is calculated as follows:

If the Checksum is sent (CHKDIS = 0):

• t_{Header_Nominal} = 34 × t_bit
• t_{Response_Nominal} = 10 × (NData + 1) × t_bit
• t_{Frame_Maximum} = 1.4 × (t_{Header_Nominal} + t_{Response_Nominal} + 1)⁽¹⁾
• t_{Frame_Maximum} = 1.4 × (34 + 10 × (DLC + 1 + 1) + 1) × t_bit
• t_{Frame_Maximum} = (77 + 14 × DLC) × t_bit

If the Checksum is not sent (CHKDIS = 1):

• t_{Header_Nominal} = 34 × t_bit
• t_{Response_Nominal} = 10 × NData × t_bit
• t_{Frame_Maximum} = 1.4 × (t_{Header_Nominal} + t_{Response_Nominal} + 1)⁽¹⁾
• t_{Frame_Maximum} = 1.4 × (34 + 10 × (DLC + 1) + 1) × t_bit
• t_{Frame_Maximum} = (63 + 14 × DLC) × t_bit