User's Manual

9/29/2004 OV4F2
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User Manual BCM2035
04/23/03
Broadcom Corporation
Document 2035-UM100-R EEPROM Configuration Page 29
The PCM_SYNC signal supports two different sync formats - Long Sync, and Short Sync. The Long Sync
format generates or expects (depending on Master or Slave operation) a rising edge on the PCM_SYNC signal
at the beginning of the first bit of the first time slot, and generates or expects the falling edge of the PCM_SYNC
signal after the third bit of the first time slot. The Short Sync format generates or expects a one bit wide pulse
during the last bit of the last time slot (i.e. the bit just before the first bit of the first time slot).
Detailed timing diagrams for the PCM interface modes are provided in the
BCM2035 data sheet.
EEPROM CONFIGURATION
The
BCM2035 may store configuration information in an external EEPROM. This is particularly useful in a USB
PC application in which it may not be desirable for the HOST to download configuration information each time
the
BCM2035 is powered up.
Two I/O pins, EEPROM_CLK and EEPROM_DATA, are provided for the connection to an EEPROM that
supports I2C serial interface. The EEPROM_DATA signal is open drain and requires a pull-up resistor, whether
or not an EEPROM is present. The EEPROM_CLK signal is an output from the
BCM2035 that controls the
clock for the serial EEPROM.
Figure 13 and Figure 14 on page 30 show the connectivity of BCM2035 pins (EEPROM_CLK and
EEPROM_DATA) for system with and without EEPROM respectively.
Figure 13: BCM2035 Connection to EEPROM
EEPROM_DATA
EEPROM_CLK
BCM2035
EEPROM
DATA
CLK
10k
VDD_IO