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10.4.5 High Speed Mode

The N40P112 is capable to work in HS-mode.

For switching to HS-mode the Master has to send the sequence: START, MASTER CODE, NACK. This sequence is sent in FS-mode. As no

device is allowed to acknowledge the master code, the master code is followed by a not-acknowledge. After a device receives the master code it

receive a STOP command. After receiving a STOP command it has to switch back form HS-settings to FS-settings, which has to be competed

When switching to HS-mode the slave has to

Adapt the SDAH and SCLH input filters according to the spike suppression requirement required in HS-mode. In HS-mode spikes up to

10ns, in FS-mode spikes up to 50ns have to be suppressed.

Adapt the setup and hold times according to the HS-mode requirement. In HS-mode an internal hold time for SDA for START/STOP

detection of 80ns (max. 150ns), in FS-mode an internal hold time of 160ns (max. 250ns) has to be provided.

Adapt the slope control for SDAH output stage.

Figure 15. Data Transfer Format in HS-mode

Figure 16. A Complete HS-mode Transfer

S

Master code

NA Sr

Slave Address R/W

DATA

A/

NA

Slave Address

Sr

F/S mode

Hs mode (current source for SCLH enabled)

P

A

F/S mode

Hs mode continues

< n bytes + ack >