
Static Memory Interface
9-3
GMS30C7201 Data Sheet
9.2
Hardware Interface and Signal Description
The Static Memory Controller module is connected to the ASB bus.
Table 9-1: Static
Memory Controller ASB signal descriptions
shows the internal bus interface signals
to the Static Memory Controller.
Name
Type
Description
BA[28:26, 5:0]
In
System address bus.
BD[10:0]
InOut
Bidirectional system data bus.
BCLK
In
The ASB system clock
BnRES
In
AMBA asynchronous reset. This signal is negative active.
BWAIT
Out
This slave response signal is driven when the BUSC is
selected, and is used to indicate if the memory has
completed its current transfer.
BERROR
Out
Slave response signal.
BLAST
Out
Slave response signal.
BSIZE[1:0]
In
The signals indicate the size of the transfer, which may be
byte, halfword or word.
BTRAN[1:0]
In
These signals are used to determine access type.
BWRITE
In
When LOW, Read; when HIGH, Write.
DSELSRAM
In
When HIGH, this signal indicates that the Bus controller is
selected.
DSELREG
In
When HIGH, this signal indicates that one of the bank
configuration registers is selected.
EXPRDY
In
Expansion channel ready. When LOW, during phase one
this signal will force the current memory transfer to be
extended.
nWEN[3:0]
Out
These signals are active LOW write enables for each of the
memory byte lanes on the external bus.
nWEF[3:0]
In
These optional connections use PADs feedback from the
external side of the nWEN[3:0] PADs. They are used to
guarantee address and chip select hold time when any write
enable is LOW.
nSRAMOE
Out
This is the active LOW output enable for devices on the
external bus.
nCS[5:0]
Out
Active LOW chip selects.
SRAMA[1:0]
Out
These signals form the lower bits of the external address
bus. They are used to control accesses to 16- or 8-bit
memories when the bus requests an access size larger than
the memory.
nSRAMALatch
Out
When LOW, transparent address latch enable.
Table 9-1: Static Memory Controller ASB signal descriptions