Specifications
28 SAM0023-122898 ESS Technology, Inc.
ES1869 DATA SHEET
PNP CONFIGURATION AND REGISTERS
PNP CONFIGURATION AND REGISTERS
Figure 20 shows the configuration register set that is
discussed in the following pages. As shown below, the
Card-Level registers supported by the ES1869 are the
Card-Control Card-Level registers at addresses 00h-07h,
and the Vendor-Defined Card-Level registers at
addresses 20h-2Fh. The Card-Control Card-Level register
at address 07h is a pointer to the Logical Device registers
supported by the ES1869 (one set of registers for each
logical device on the “card”). In the ES1869, there are six
logical devices: the configuration device, the
audio+FM+MPU-401 device, the joystick device, the CD-
ROM device, the Modem device, and a user-defined
General-Purpose device.
Figure 20 Configuration Register SeAccess to PnP Registers
Configuration Ports
To directly access the PnP registers, and bypass the PnP
sequence, write a special key sequence to port 279h that
depends on bits 6:5 of PnP register 25h, and conclude
with two I/O writes to 279h to set the base address of the
configuration ports. The key sequence also sets the
activate bit for the configuration device.
Bypass Key
If PnP is not supported by the system, it is possible to
bypass PnP by issuing a special “bypass key” to the
ES1869 to force the configuration device to be enabled at
a specific l/O address. The ES1869 must be in the “wait-
for-key” Plug and Play state. The special key is 32 bytes
long, written to the PnP address register (279h). Follow
the bypass key immediately with two I/O writes to the PnP
address register to set the low and high bytes of the
address register of the configuration device. The bypass
key also activates the configuration device. The address
of the configuration device must be in the range 100h-
FF8h, aligned on a multiple of 8. An “alias” of the audio
device address can be used. For example, use E20h for
the configuration device if the audio device address is at
220h.
The actual key sequence is determined by the state of bits
5 and 6 of Vendor-Defined Card-Level register 25h. These
bits are both zero after reset, and are loaded from the
seventh byte of the PnP ROM header (if the first byte of
the header is 'A5'). The purpose of the bypass key is to
handle the case where multiple instances of the ES1869
coexist in a single non-PnP system. It is recommended to
try all four keys successively. The only difference between
the four keys are the two least significant bits: XOR bits 1
and 0 of key #0 with bits 5 and 6 of register 25h to generate
keys #1, #2, and #3.
NOTE: Perform the entire sequence with interrupts
disabled to minimize the chance that an interrupt corrupt
the sequence.
Register 25h, bits 6:5 = 0,0
66, a1, c2, f1, ea, e7, 71, aa
c7, 63, 33, 1b, d, 96, db, 6d
a4, 50, 28, 16, 9b, 4d, b6, c9
f4, 78, 3e, 8d, d6, fb, 7f, 3d
<config_address_low>, <config_address_high>
Register 25h, bits 6:5 = 0,1
67, a0, c3, f0, eb, e6, 70, ab
c6, 62, 32, 1a, c, 97, da, 6c
a5, 51, 29, 17, 9a, 4c, b7, c8
f5, 79, 3f, 8c, d7, fa, 7e, 3c
<config_address_low>, <config_address_high>
Register 25h, bits 6:5 = 1,0
Address
00h
01h
02h
03h
04h
05h
06h
07h
Address
30h
31h
32h
37h
Set Read Port Address
Serial Isolation
Configuration Control
Wake Command [CSN]
Resource Data
Status
Card Select Number (CSN)
Logical Device Number
Reserved
Card-Level
Registers
Vendor-Defined
Card-Level
Registers
Vendor-Defined
Logical Device
Control
Activate
I/O Range Check
Reserved for
Logical Device
Control
ISA Memory
Configuration
Registers 3:0
I/O Configuration
Registers 7:0
Interrupt Configuration
Registers 1:0
DMA Configuration
Registers 1:0
32-bit Memory
Configuration
Reserved for
Logical Device
Configuration
Vendor-Defined
Logical Device
Configuration
Reserved
Registers 1:0
38h
3Fh
70h
73h
60h
6Fh
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•
•
40h
5Fh
A9h
EFh
F0h
FEh
76h
A8h
74h
75h
FFh
08h
1Fh
20h
2Fh
Card-Level Registers
(one set per card)
Logical Device Registers
(one set per logical device on card)
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8 bits
7 0
8 bits
7 0
Card-Control Card-Level Registers