
ISA Plug and Play Interface
5-26
MC68SC302 USER’S MANUAL
MOTOROLA
5.8 ISA-PNP CONTROL REGISTERS SUMMARY
Table 5-5. Card Level Control Registers Summary
NAME
ADDRESS
PORT VALUE
DESCRIPTION
ACTIVE IN THE
FOLLOWING
STATES
Set RD_DATA port
0x00
Writing this location modifies the READ_DATA port ad-
dress. Bits[7:0] become bits[9:2] of the address. Bits[1:0]
of the address set 2’b11. The register is write only.
See
5.14 Isolation Protocol. The register is read only.
Bit[2] - Reset CSN to 0 (all the cards)
Bit[1] - Return to the Wait for Key state (always active, all
the cards)
Bit[0] - Reset all the logical devices and restore the con-
tents of configuration registers to their default state. CSN
is preserved. The software must delay 2+ ms after issu-
ing Reset command before accessing ISA-PNP ports.
The register is write-only. The Bits[7:3] are reserved.
If WRITE_DATA[7:0] == card’s CSN, then goto from
Sleep to Configuration (if CSN <> 0) or goto Isolation (if
CSN == 0). If (WRITE_DATA[7:0]<> 0) and
(WRITE_DATA[7:0] <> CSN) and the card is in the con-
figuration state, it transitions to the Sleep state. Pointer to
Serial EPROM (or another byte serial device) is always
reset. The register is write-only. If the card is in the Isola-
tion State, Wake[0] will leave the card in the Isolation
state.
A read from this register returns next byte from Serial
EPROM. Bit[0] of the status register must be polled be-
fore the read. The register is read only.
1’b1 in Bit[0] of this register is set, the Resource Data
contains a valid byte. Bits[7:1] are reserved and return
7b’000_0000. The register is read only.
The numbers 1-255 are valid (0 indicates un-isolated
card). writing this register at the end of Isolation, causes
transition to the Configuration State. The register resets
at RESET_DRV and Reset CSN command. The register
is read/write.
The number (0-255) in this register points to the Logical
Device, next commands will operate on. The chip is in-
tended to support 1 logical device, so this register is
read-only and returns 0x00 on a read access.
Reserved for future use(unimplemented). On reads re-
turn 0.
ICHRDY-enables wait states on ISA-bus accesses to the
Internal space.
ECHRDY-the same for CS0.
SCP_BS-indicates that the access to SCP is prohibited.
CLKCNT (Clock Control): controls power management
functions.
The rest of bits are unimplemented and on reads return
0.
The initial values of these register is loaded from 0x07 of
a byte serial device.
Bits[7:6] - I/O Memory configuration selectors for Internal
space (bit[7]) and CS0 (bit[6]).1=Memory mode; 0=I/O
mode.
Bits[5:4] - If the I/O mode is chosen these bits are valid
and indicate the data width of Internal space (bit[5]) and
CS0 space (bit[4]).1=16-bit data width; 0=8-bit data
width.
Bits[2:0] - Encoded Range Length Mask. See ISI register
definition for details.
Isolation,
Configuration
Serial Isolation
0x01
Isolation
Configuration Control
0x02
In any state, except
Wait for Key.
Wake[CSN]
0x03
Sleep, Isolation,
Configuration
Resource Data
0x04
Configuration
Status
0x05
Configuration
Card Select Number
0x06
End of Isolation,
Con-
figuration
Logical Device Number
0x07
Configuration
Card Level Reserved
0x08-0x1F
Configuration
BUSCNT
0x20
Configuration
CLKCNT
0x21
Configuration
ISI (Implementation
Specific Information)
0x22
Configuration
Card Level Vendor De-
fined Registers
0x23-2F
Unimplemented. On reads return 0.
Configuration