GPMC_FCLK
GPMC_CLK
WAIT
Valid Address
Data 0
Data 0
CSONTIME
CSRDOFFTIME
ADVONTIME
ADVRDOFFTIME
OEONTIME
OEOFFTIME
RDACCESSTIME
RDCYCLETIME
nBE1/nBE0
nCS
nADV
nOE
gpmc_a[11:1]
gpmc_d[15:0]
(connected to A[9:0] on
memory side)
(connected to D[15:0] on
memory side)
gpmc-010
Public Version
www.ti.com
General-Purpose Memory Controller
10.1.5.7 WRITE PROTECT (nWP)
When connected to the attached memory device, the WRITE PROTECT signal can enable or disable the
lockdown function of the attached memory.
The gpmc_nwp output pin value is controlled through the GPMC.
[4] WRITEPROTECT bit,
which is common to all CS.
10.1.5.8 BYTE ENABLE (nBE1/nBE0)
BYTE ENABLE signals (nBE1/nBE0) are:
•
Valid (asserted or nonasserted according to the incoming system request) from access start to access
completion for asynchronous and synchronous single accesses
•
Asserted low from access start to access completion for asynchronous and synchronous multiple read
accesses
•
Valid (asserted or nonasserted, according to the incoming system request) synchronously to each
written data for synchronous multiple write accesses
10.1.5.9 Asynchronous Access Description
In asynchronous operations:
•
GPMC_CLK is not provided outside the GPMC.
•
GPMC_CLK is kept low.
10.1.5.9.1 Asynchronous Single Read
10.1.5.9.1.1 Asynchronous Single Read Operation on a Nonmultiplexed Device
shows an asynchronous single read operation on a nonmultiplexed device.
Figure 10-10. Asynchronous Single Read on an Address/Data-Nonmultiplexed Device
2141
SWPU177N – December 2009 – Revised November 2010
Memory Subsystem
Copyright © 2009–2010, Texas Instruments Incorporated