AT49LH00B4-33TC ATMEL [ATMEL Corporation], AT49LH00B4-33TC Datasheet - Page 14
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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)
LPC Write Cycle
Figure 6. LPC Write Cycle
Table 9. LPC Write Cycle
Note:
14
FWH4/LFRAME
FWH/LAD[3:0]
Clock Cycle
3 - 10
11
12
13
14
15
16
17
1
2
1. Field contents are valid on the rising edge of the present clock cycle.
CLK
AT49LH00B4
CYCTYPE +
Field Name
MADDR
RSYNC
0000b
START
START
DATA
DATA
TAR0
TAR1
TAR0
TAR1
DIR
1
CYCTYPE
011xb
+ DIR
2
LPC write cycles are used to send commands to the device and to program data into the
memory array.
Valid LPC write cycles begin with a START field of 0000b and a CYCTYPE + DIR field of
011xb being sent to the device. Following the MADDR field, the master sends one byte of data
to the LPC device during the next two clock cycles. The data is sent one nibble at a time with
the low nibble being output first followed by the high nibble. After the data has been sent, the
master will send a 2-clock TAR field to the LPC device to indicate that it is turning control of
the bus back over to the LPC device. After the second clock of the TAR phase, the LPC device
assumes control of the bus and drives a “ready” SYNC field to verify that it has received the
data. The LPC device will then send a 2-clock TAR field to the master to indicate that it is turn-
ing control of the bus back over to the master.
A31-A28
FWH/LAD[3:0]
0000b (ready)
Field Value
1111b (float)
1111b (float)
3
0000b
1111b
1111b
011xb
YYYY
YYYY
YYYY
A27-A24
4
A23-A20 A19-A16
(1)
5
Float then OUT
FWH/LAD[3:0]
OUT then float
Float then IN
IN then float
Direction
MADDR
6
OUT
A15-A12
IN
IN
IN
IN
IN
7
A11-A8
8
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 write.
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.
YYYY is the least significant nibble of the data byte. The data
byte is either any valid Flash command or the data to be
programmed into the memory array.
YYYY is the most significant nibble of the data byte.
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.
During this clock cycle, the device will generate a “ready”
SYNC indicating that the data byte has been received.
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.
A7-A4
9
A3-A0
10
D3-D0
DATA
11
D7-D4
DATA
12
1111b
TAR0
13
High-Z
TAR1
14
RSYNC
0000b
15
3379B–FLASH–9/03
1111b
TAR0
16
High-Z
TAR1
17