FlexROM III Timing Specifications

Timing Specifications

The following specifications assume:
- All Filtering has been disabled.
- The Latching options have been left at the default setting of (CS and WT active).
- Latch delay has been disabled.

Enabling Filtering and/or Latch delaying adds 10-40ns to the Tcr-2. Tcr-3 and Tcr-4 specs. Enabling Latch on (CS) or Latch on (CS and NOT OE) with MINIMUM delay selected reduces Twp to 20ns. Higher delay settings could result in longer Trdc & Twtc requirements.

Read Cycles:

Symbol	Name	Description	Value
Trdc	Read Cycle	Time for a complete read cycle	45ns (max)
Tacc	Address Access	Time from address stable to data valid	45ns (max)
Tcs	CS Access Fast-CS enabled Fast-CS disabled	Time from CS active to data valid	12 (max) 45ns (max)
Toe	CS Access Fast-OE enabled Fast-OE disabled	Time from OE active to data valid	12 (max) 30ns (max)
Todo	OE to data disable	Time from rising edge OE to data float	0 – 6ns
Tcod	CS to data disable	Time from rising edge CS to data float	0 – 12ns
Tcr-1	Cycle Recovery time, valid data	Minimum recovery after a read	0ns (min)

NOTE: Data will be valid after ALL access time specs have been meet; Tacc after address stable, Tcs after CS active and Toe after OE active.

Write Cycles (WT controlled/CS controlled):

Symbol	Name	Description	Value
Twtc	Write Cycle	Time for a complete write cycle	45ns (max)
Tas	Address Setup time	Address stable to falling edge WT/CS	0ns (min)
Tah	Address Hold time	Address held after rising edge WT/CS	0ns (min)
Tds	Data Setup time	Data stable to rising edge WT/CS	10ns (min)
Tdh	Data Hold time	Data held after rising edge WT/CS	0ns (min)
Twp	WT pulse width	Minimum WT active pulse width	25ns (min)
Todw	WT to data disable	Time from falling edge WT to data float (if CS & OE were active)	0 – 12ns
Tcr-2	Cycle recovery time, writes	Minimum recovery time after a write	20ns (min)

Snap-shot and Trigger functions

Symbol	Name	Description	Value
Tcr-3	Cycle Recovery time, reads	Minimum recovery time after a read	10ns (min)
Tcr-4	Cycle recovery time, writes	Minimum recovery time after a write	25ns (min)
Top	OE pulse width	Minimum OE active pulse	25ns (min)

NOTE: Violation of the Snap-shot/Trigger specs will not cause target side failures unless their specs are being violated as well.