AT49LH00B4-33TC ATMEL [ATMEL Corporation], AT49LH00B4-33TC Datasheet - Page 13
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AT49LH00B4-33TC
Manufacturer Part Number
AT49LH00B4-33TC
Description
4-megabit Top Boot, Bottom Partitioned Firmware Hub and Low-Pin Count Flash Memory
Manufacturer
ATMEL [ATMEL Corporation]
Datasheet
1.AT49LH00B4-33TC.pdf
(36 pages)
Figure 5. LPC Read Cycle
Table 8. LPC Read Cycle
Note:
3379B–FLASH–9/03
FWH4/LFRAME
Clock Cycle
FWH/LAD[3:0]
13 - 14
3 - 10
11
12
15
16
17
18
19
1
2
1. Field contents are valid on the rising edge of the present clock cycle.
CLK
CYCTYPE +
Field Name
0000b
START
MADDR
WSYNC
RSYNC
START
TAR0
TAR1
TAR0
TAR1
DATA
DATA
1
DIR
CYCTYPE
010xb
+ DIR
2
A31-A28
3
FWH/LAD[3:0]
0000b (ready)
Field Value
1111b (float)
1111b (float)
0101b (wait)
A27-A24
0000b
1111b
1111b
010xb
YYYY
YYYY
YYYY
4
A23-A20 A19-A16
5
(1)
MADDR
6
Float then OUT
FWH/LAD[3:0]
OUT then float
Float then IN
A15-A12
IN then float
Direction
7
OUT
OUT
OUT
OUT
IN
IN
IN
A11-A8
8
A7-A4
9
Comments
FWH4/LFRAME must be active (low) for the device to
respond. Only the last START field (before FWH4/LFRAME
transitioning high) should be recognized. The START field
contents indicate an LPC cycle.
Indicates that the cycle type is an LPC memory cycle and the
direction of the transfer is a read.
These eight clock cycles make up the 32-bit memory address.
YYYY is one nibble of the entire address. Addresses are
transferred with the most significant nibble first.
In this clock cycle, the master has driven the bus to all 1s and
then floats the bus prior to the next clock cycle. This is the first
part of the bus “turn-around cycle”.
The device takes control of the bus during this clock cycle.
The device outputs the value 0101b, a “wait” SYNC, for two
clock cycles. This value indicates to the master that data is not
yet available from the device. This number of wait-syncs is a
function of the device’s memory access time.
During this clock cycle, the device will generate a “ready”
SYNC indicating that the least significant nibble of the data
byte will be available during the next clock cycle.
YYYY is the least significant nibble of the data byte.
YYYY is the most significant nibble of the data byte.
The LPC memory device drives the bus to 1111b to indicate a
turn-around cycle.
The LPC memory device floats its outputs, and the master
regains control of the bus during this clock cycle.
A3-A0
10
1111b
TAR0
11
High-Z
TAR1
12
WSYNC
0101b
13
WSYNC
0101b
14
RSYNC
0000b
15
AT49LH00B4
D3-D0
DATA
16
D7-D4
DATA
17
1111b
TAR0
18
High-Z
TAR1
19
13