cs4239 Cirrus Logic, Inc., cs4239 Datasheet - Page 86

• Manufacturer Part Number: cs4239
• Description: Crystalclear? Ortable Isa Audio System Logic
• Manufacturer: Cirrus Logic, Inc.

MIDI Interface
MIDOUT - MIDI Out Transmit Data, Output, 4 mA drive
MIDIN - MIDI In Receive Data, Input - Internal Pullup
External Peripheral Signals
SDA - E
XCTL0 - External Control, Output, 4 mA drive
SCL - E
BRESET - Buffered Reset, Output, 4 mA drive
86
This output is used to send MIDI data serially out to a external MIDI device. Normally
connected to pin 12 of the joystick connector for use with breakout boxes, as well as on-board
synthesizers.
This input is used to receive serial MIDI data from an external MIDI device. This pin should be
connected to pin 15 of the joystick connector for use with breakout boxes.
This open-drain pin must have an external pullup (3.3 k ) and is used in conjunction with SCL
to access an external serial E
connected to the data pin of the E
E
This pin is a general purpose output pin controlled by the XCTL0 bit in the WSS register I10.
When E
output to the E
selects between two alternate addresses for the Address Port used to configure the chip.
Assuming APSEL is strapped low, SCL high selects 308h as the Address Port, and when SCL is
tied low (with a 10 k resistor to ground), the Address Port is 388h.
This active low signal goes low whenever the RESDRV pin goes high. This pin is also software
controllable through the BRES bit in register C8 in the Control Logical Device space. BRES
provides a software power down and reset control over devices connected to the CS4239 such
as the CS9236 Single-Chip Wavetable Music Synthesizer.
2
2
2
PROM Serial Clock, Output, 4 mA drive (Address Port Selection)
PROM Data Pin, Bi-directional, Open Drain, 4 mA sink
PROM is used to set the Plug and Play resource data.
2
PROM access is enabled, via EEN in CTRLbase+1, then SCL is used as a clock
2
PROM. At power-up, this pin is an input (with an internal 100 k
2
PROM. When an E
2
PROM device and provides a bi-directional data port. The
2
PROM is used, the SDA pin should be
CrystalClear Portable ISA Audio System
TM
pullup) that
CS4239
DS253PP2