Specifications

ESS Technology, Inc. SAM0025A-062397 41
ES1879 DATA SHEET
I/O PORTS
PRELIMINARY
I/O PORTS
Port Descriptions
This section describes the I/O ports in detail.
Configuration Device
Logical device 0 is the configuration device. It has eight I/
O Configuration Device ports assigned to it. Two of these
ports are used to access a set of Plug and Play registers
that define I/O resources and activation controls for audio,
FM, MPU-401, and joystick devices.
Configuration Register Address (Config_Base+0h, R/W)
Sets the PnP configuration address.
Configuration Register Data (Config_Base+1h, R/W)
Sets the PnP configuration data.
ES1879 GPO State Register (Config_Base+2h, R/W)
Sets the state of the ES1879 GPO pins that are not
mapped to GPI pins of the ES978.
Table 14 I/O Ports for Configuration, Audio, FM, MPU-401, and Joystick Devices
Port Read/Write Function
Configuration Device
Base+0h Read/write Configuration Register Address.
Base+1h Read/write Configuration Register Data.
Base+2h Read/write ES1879 GPO State register.
Base+3h Read/write ES978 GPO State register.
Base+4h Read-only ES1879 GPI Status register.
Base+5h Read-only ES978 GPI Status register.
Base+6h Read-only Interrupt Status register.
Base+7h Read/write Interrupt Mask register.
Audio Device
Base+0h - Base+3h Read/write 20-voice FM synthesizer. Address and data registers.
Base+4h Read/write Mixer Address register (port for address of mixer controller registers).
Base+5h Read/write Mixer Data register (port for data to/from mixer controller registers).
Base+6h Read/write Audio reset and status flags.
Base+7h Read/write Power Management register. Suspend request and FM reset.
Base+8h - Base+9h Read/write 11-voice FM synthesizer. Address and data registers.
Base+Ah Read-only Input data from read buffer for command/data I/O. Poll bit 7 of port Audio_Base+Eh to test
whether the read buffer contents are valid.
Base+Ch Read/write Output data to write buffer for command/data I/O. Read embedded microcontroller status.
Base+Eh Read-only Data available flag from embedded microcontroller.
Base+Fh Read/write Address for I/O access to FIFO in Extended mode.
FM Device
Base+0h - Base+3h Read/write 20-voice FM synthesizer. Address and data registers.
MPU-401 Device
Base+0h - Base+1h Read/write MPU-401 port (x=0,1, 2, or 3) if enabled.
Joystick Device
Base+0h Read/write Joystick.
A7 A6 A5 A4 A3 A2 A1 A0
76543210
D7 D6 D5 D4 D3 D2 D1 D0
76543210
x GPO6 GPO5 GPO4 GPO3 GPO2 GPO1 GPO0
76543210