Specifications

32 SAM0025A-062397 ESS Technology, Inc.
ES1879 DATA SHEET
CONFIGURATION
PRELIMINARY
Card-Control Card-Level Registers (00h – 07h)
This section describes the PnP Card registers of the
ES1879.
Set RD_DATA Port (00h, R/W)
The PnP read port can be written only when the card is in
Isolation mode. It is reset low by hardware reset. It can be
read only from Configuration mode. Bits 1:0 of PnP read
port are always one.
Serial Isolation (01h, R)
Read-only in isolation state. Used to read the serial
identifier during the card isolation process.
Config Control (02h, W)
Bit Definitions:
Wake[CSN] (03h, W)
If data written is 00h and it:

matches the CSN:
this card goes from Sleep mode to Isolation mode.

does not match the CSN:
this card goes from Configuration mode to Sleep
mode.
If the data written is non zero, and it:

matches the CSN:
this card goes from Sleep mode to Configuration mode.

does not match the CSN:
this card goes from Isolation mode to Sleep mode.
Resource Data (04h, R)
Returns next byte of resource data, provided the status bit
in register 05h has been polled before each byte read,
indicating that data is ready. Only works in Configuration
mode.
Status (05h, R)
Bit Definitions:
CSN (06h, R/W)
Read/Write card select number. Write only works in
Isolation mode. Causes transition to Configuration mode.
Read works only in Configuration mode.
LDN (07h, R/W)
Read/Write logical device number. Only works in
Configuration mode.
LDN 0 Configuration device
LDN 1 Audio/FM device
LDN 2 Joystick device
LDN 3 MPU-401 device (only if bit 7 of Vendor
register 25h is high)
Bits 9:2 of the PnP RD_DATA port
765432 1 0
Data
765432 1 0
x x x x x RESET_CSN WFK SWR
76543 2 1 0
Bits Name Description
7:3 – Don’t care.
2 RESET_CSN RESET_CSN command.
1 = Card’s CSNs set to zero.
1 WFK WAIT_FOR_KEY command.
1 = Enter wait-for-key state.
0 SWR Software reset command. Does not work
in wait-for-key state.
1 = Reset config registers to default.
Data
765432 1 0
Resource data
765432 1 0
0Status
76543210
Bits Name Description
7:1 – Reserved. Always write 0.
0 Status 1 = Ready to read resource data from register
04h. Only works in Configuration mode.
0 = Resource data not available.
Card select number
76543210
Logical device number
76543210