TC1796
System Units (Vol. 1 of 2)
LMB External Bus Unit
User’s Manual 13-77 V2.0, 2007-07
EBU, V2.0
only effect on operation is that the number of overrun cycles will increase as the
decrementing of the sample counter will be lagged by the re-synchronization stages.
13.9.11.2 Terminate and Start New Burst Mode
In Terminate and Start New Burst Mode, the WAIT input being asserted low during a
burst access causes the EBU to complete the current Burst Phase and then to terminate
the current access. If additional data is required, the EBU will start a new access cycle
(i.e. Address Phase, Command Delay Phase, Command Phase, Burst Phase etc.).
Furthermore, the EBU calculates the address to be issued during the new Address
Phase to ensure correct sequential reading of the Burst Flash device(s). This mode
allows, for example, an AMD Burst Flash device to cause the EBU to terminate the
current access when a page boundary is crossed, and to issue a complete new burst
read access. This allows the Burst Flash device to perform a page load at the start of the
new access.
All current known devices require EBU_BUSCON.WAIT to be set to 10
B
(standard wait).
There are no devices currently known requiring BUSCON.WAIT to be set to 01
B
(early
wait).
Note: The Terminate and Start New Burst Mode cannot be used with clock feedback.