Datasheet

11AA02E48/11AA02E64
DS20002122B-page 10  2008-2013 Microchip Technology Inc.
4.2 Current Address Read (CRRD)
Instruction
The internal address counter featured on the
11AA02EXX maintains the address of the last memory
array location accessed. The CRRD instruction allows
the master to read data back beginning from this
current location. Consequently, no word address is
provided upon issuing this command.
Note that, except for the initial word address, the
READ and CRRD instructions are identical, including
the ability to continue requesting data through the use
of MAKs in order to sequentially read from the array.
As with the
READ instruction, the CRRD instruction is
terminated by transmitting a NoMAK.
Table 4-2 lists the events upon which the internal
address counter is modified.
TABLE 4-2: INTERNAL ADDRESS
COUNTER
FIGURE 4-2: CRRD COMMAND SEQUENCE
Command Event Action
— Power-on Reset Counter is undefined
READ or
WRITE
MAK edge
following each
Address byte
Counter is updated
with newly received
value
READ,
WRITE, or
CRRD
MAK/NoMAK
edge following
each data byte
Counter is incre-
mented by 1
Note: If, following each data byte in a
READ,
WRITE, or CRRD instruction, neither a
MAK nor a NoMAK edge is received (i.e.,
if a standby pulse occurs instead), the
internal address counter will not be incre-
mented.
Note: During a Write command, once the last
data byte for a page has been loaded, the
internal Address Pointer will rollover to the
beginning of the selected page.
7654
Data Byte 1
3210 7654
Data Byte 2
3210
7654
Data Byte n
3210
SCIO
MAK MAK
NoMAK
11010100
Start Header
SCIO
Device Address
MAK
00001010
MAK
Command
10000001
MAK
NoSAK
SAK
Standby Pulse
SCIO
SAK SAK SAK
SAK