Table 2. mux/bits clock selection – Cirrus Logic CS61880 User Manual
Page 11

CS61880
DS450PP3
11
MUX/BITSEN0
43
K2
I
Multiplexed Interface/Bits Clock Select
Host Mode -This pin configures the microprocessor inter-
face for multiplexed or non-multiplexed operation. 
Hardware mode - This pin is used to enable channel 0 as 
a G.703 BITS Clock recovery channel (Refer to 
INTEGRATED TIMING SYSTEMS (BITS) CLOCK MODE
(See Section 8 on page 23). Channel 1 through 7 are not 
affected by this pin during hardware mode. During host 
mode the G.703 BITS Clock recovery function is enabled by 
the 
Bits Clock Enable Register (1Eh)
NOTE: The MUX pin only controls the BITS Clock function in
Hardware Mode
INT
82
K13
O
Interrupt Output
This active low output signals the host processor when one 
of the CS61880’s internal status register bits has changed 
state. When the status register is read, the interrupt is 
cleared. The various status changes that would force INT 
active are maskable via internal interrupt enable registers.
NOTE: This pin is an open drain output and requires a 10 k
Ω
pull-up resistor.
RDY/ACK/SDO
83
K14
O
Ready/Data Transfer Acknowledge/Serial Data Output
Intel Parallel Host Mode - During a read or write register 
access, RDY is asserted “Low” to acknowledge that the de-
vice has been accessed. An asserted “High” acknowledges 
that data has been written or read. Upon completion of the 
bus cycle, this pin High-Z.
Motorola Parallel Host Mode - During a data bus read 
operation this pin, “ACK”, is asserted “High” to indicate that 
data on the bus is valid. An asserted “Low” on this pin dur-
ing a write operation acknowledges that a data transfer to 
the addressed register has been accepted. Upon comple-
tion of the bus cycle, this pin High-Z. 
NOTE: Wait state generation via RDY/ACK is disabled in 
RZ mode (No Clock Recovery).
Serial Host Mode - When the microprocessor interface is 
configured for serial bus operation, “SDO” is used as a seri-
al data output. This pin is forced into a high impedance 
state during a serial write access. The CLKE pin controls 
whether SDO is valid on the rising or falling edge of SCLK. 
Upon completion of the bus cycle, this pin High-Z.
Hardware Mode - This pin is not used and should be left 
open.
SYMBOL
LQFP
FBGA
TYPE
DESCRIPTION
Table 2. Mux/Bits Clock Selection
Pin State
Parallel Host Mode
Hardware Mode
HIGH
multiplexed
BITS Clock ON
LOW
non multiplexed
BITS Clock OFF
