Datasheet

Instructions M24C04-W M24C04-R M24C04-F
16/34 DocID023994 Rev 3
5.1.3 Minimizing Write delays by polling on ACK
The maximum Write time (t
w
) is shown in AC characteristics tables in Section 8: DC and AC
parameters, but the typical time is shorter. To make use of this, a polling sequence can be
used by the bus master.
The sequence, as shown in Figure 7, is:
• Initial condition: a Write cycle is in progress.
• Step 1: the bus master issues a Start condition followed by a device select code (the
first byte of the new instruction).
• Step 2: if the device is busy with the internal Write cycle, no Ack will be returned and
the bus master goes back to Step 1. If the device has terminated the internal Write
cycle, it responds with an Ack, indicating that the device is ready to receive the second
part of the instruction (the first byte of this instruction having been sent during Step 1).
Figure 7. Write cycle polling flowchart using ACK
Write cycle
in progress
A
I01847d
AI01847e
Next
Operation is
addressing the
memory
Start condition
Device select
with RW = 0
ACK
returned
YES
NO
YESNO
ReStart
Stop
Data for the
Write cperation
Device select
with RW = 1
Send Address
and Receive ACK
First byte of instruction
with RW = 0 already
decoded by the device
YESNO
StartCondition
Continue the
Write operation
Continue the
Random Read operation