MX23L12854 Macronix International, MX23L12854 Datasheet - Page 8

• Manufacturer Part Number: MX23L12854
• Description: 128M-BIT Low Voltage / Serial Mask ROM Memory with 50MHz SPI Bus Interface
• Manufacturer: Macronix International

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DataSheet
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Read Data Bytes at Higher Speed (FAST_READ)
The device is first selected by driving Chip Select (S#)
Low. The instruction code for the Read Data Bytes at
Higher Speed (FAST_READ) instruction is followed by a 3-
byte address (A23-A0) and a dummy byte, each bit being
latched-in during the rising edge of Serial Clock (C). Then
the memory contents, at that address, is shifted out on
Serial Data Output (Q), each bit being shifted out, at a
maximum frequency fC, during the falling edge of Serial
Clock (C).
The instruction sequence is shown in Figure 5. The first
byte addressed can be at any location. The address is
Figure 5. Read Data Bytes at Higher Speed (FAST_READ) Instruction Sequence and Data-Out
Sequence
P/N: PM1141
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S#
C
D
Q
S#
C
D
Q
0
7
1
32 33 34
High Impedance
6
2
Instruction
Dummy Byte
5
3
4
35
4
3
5
36 37 38 39 40 41 42 43 44 45 46
2
6
1
7
23
0
8
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MSB
22 21
7
9 10
24 BIT ADDRESS
6
DATA OUT 1
5
3
28 29 30 31
4
8
2
3
automatically incremented to the next higher address after
each byte of data is shifted out. The whole memory can,
therefore, be read with a single Read Data Bytes at Higher
Speed (FAST_READ) instruction. When the highest ad-
dress is reached, the address counter rolls over to 000000h,
allowing the read sequence to be continued indefinitely.
The Read Data Bytes at Higher Speed (FAST_READ)
instruction is terminated by driving Chip Select (S#) High.
Chip Select (S#) can be driven High at any time during data
output.
1
2
0
1
0
47
MSB
7
6
MX23L12854
DATA OUT 2
5
4
3
2
1
0
MSB
7
REV. 1.1, MAY. 04, 2005