Functional Overview
Note
In
smc_data_out_0[31:0] output bus. Read data is accepted on the smc_data_in_0[31:0]
bus.
Asynchronous write
Table 2-6 and Table 2-7 list the smc_opmode0_<0-3> and SRAM Register settings.
Table 2-6 Asynchronous write opmode chip register settings
Field | mw | rd_sync | rd_bl | wr_sync | wr_bl | baa | adv | bls | ba | ||
|
|
|
|
|
|
|
|
|
|
|
|
Value | - | - |
| - |
| b0 | b000 | - | - | - | - |
|
|
| |||||||||
| Table | ||||||||||
|
|
|
|
|
|
|
|
|
|
| |
|
|
| Field | t_rc | t_wc | t_ceoe | t_wp |
| t_pc | t_tr | |
|
|
|
|
|
|
|
|
|
|
| |
|
|
| Value | - | b0100 | - | b010 |
| - | - | |
|
|
|
|
|
|
|
|
|
|
|
|
Figure 2-16 shows an asynchronous write with a write cycle time tWC of four cycles and a smc_we_n_0 assertion duration, tWP, of two cycles.
Note
The timing parameter tWC is controlling the deassertion of smc_we_n_0. You can use it to vary the hold time of smc_cs_n_0[3:0], smc_add_0[31:0] and smc_data_out_0[31:0]. This differs from the read case where the timing parameter tCEOE controls the delay in the assertion of smc_oe_n_0. Additionally, smc_we_n_0 is always asserted one cycle after smc_cs_n_0[3:0] to ensure the address bus is valid.
VPFBPFON |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| ||
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| ||
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| W:& |
|
|
|
|
|
|
|
|
|
| ||
VPFBFVBQB>@ |
|
|
|
|
|
|
|
| |||||||||||||||
|
|
|
|
|
|
|
|
|
|
|
|
| |||||||||||
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| |
|
|
|
|
|
|
|
|
|
| W:3 |
|
|
|
|
|
|
|
|
|
|
| ||
VPFBZHBQB |
|
|
|
|
|
|
|
|
|
|
|
| |||||||||||
|
|
|
|
|
|
|
|
|
|
|
|
| |||||||||||
VPFBDGGB>@ | $ |
|
|
|
|
|
|
|
|
|
| ||||||||||||
VPFBGDWDBRXWB>@ | ' |
|
|
|
|
|
|
|
|
|
|
Figure 2-16 Asynchronous write
Copyright © 2006 ARM Limited. All rights reserved. | ARM DDI 0389B |