Digi NS9215 Computer Hardware User Manual


 
TIMING
Memory Timing
494 Hardware Reference NS9215
Values in SRAM
timing diagrams
The next table describes the values shown in the SRAM timing diagrams.
Notes:
1 The (CPU clock out / 2) signal is for reference only.
2 Only one of the four dy_cs_n signals is used. The diagrams show the active low configuration, which can be
reversed (active high) with the PC field.
3 Use this formula to calculate the length of the st_cs_n signal: Tacc + board delay + (optional buffer delays,
both address out and data in) + 10ns
Parm Description Min Max Unit Notes
M15 clock high to data out valid -2 +2 ns
M16 data out hold time from clock high -2 +2 ns
M17 clock high to address valid -2 +2 ns
M18 address hold time from clock high -2 +2 ns
M19 clock high to st_cs_n low -2 +2 ns 2
M20 clock high to st_cs_n high -2 +2 ns 2
M21 clock high to we_n low -2 +2 ns
M22 clock high to we_n high -2 +2 ns
M23 clock high to byte_lanes low -2 +2 ns
M24 clock high to byte_lanes high -2 +2 ns
M25 data input setup time to rising clk 10 ns
M26 data input hold time to rising clk 0 ns
M27 clock high to oe_n low -2 +2 ns
M28 clock high to oe_n high -2 +2 ns