User guide

CS4341

DS298F5 21

4.9.1 Rise Time for Control Port Clock

When excess capacitive loading is present on the I²C clock line, pin 6 (SCL/CCLK) may not have

sufficient hysteresis to meet the standard I²C rise time specification. This prevents the use of com-

mon I²C configurations with a resistor pull-up. A workaround is achieved by placing a Schmitt Trig-

ger buffer, a 74HC14 for example, on the SCL line just prior to the CS4341. This will not affect the

operation of the I²C bus as pin 6 is an input only.

4.9.2 Memory Address Pointer (MAP)

The MAP byte precedes the control port register byte during a write operation and is not available

again until after a start condition is initiated. During a read operation the byte transmitted after the

ACK

will contain the data of the register pointed to by the MAP (see section 4.9.3 for write/read

details).

4.9.2a INCR (Auto Map Increment)

The device has a MAP auto increment capability enabled by the INCR bit (the MSB) of the MAP.

If INCR is set to 0, MAP will stay constant for successive I²C writes or reads and SPI writes. If INCR

is set to 1, MAP will auto increment after each byte is written, allowing block reads or writes of suc-

cessive registers.

Default = ‘0’

0 - Disabled

1 - Enabled

4.9.2b MAP0-3 (Memory Address Pointer)

Default = ‘0000’

4.9.3 I²C Mode

In the I²C Mode, data is clocked into and out of the bi-directional serial control data line, SDA, by

the serial control port clock, SCL. There is no CS

pin. Pin AD0 enables the user to alter the chip

address (001000[AD0][R/W

]) and should be tied to VA or AGND as required, before powering up

the device. If the device ever detects a high to low transition on the AD0/CS

pin after power-up,

SPI mode will be selected.

76543210

INCR Reserved Reserved Reserved MAP3 MAP2 MAP1 MAP0

00000000

Pin 6

SCL

Figure 21. I²C Buffer Example