ELANSC310 AMD [Advanced Micro Devices], ELANSC310 Datasheet - Page 100

• Manufacturer Part Number: ELANSC310
• Description: Single-Chip, 32-Bit, PC/AT Microcontroller
• Manufacturer: AMD [Advanced Micro Devices]

Notes:
Fast ROM cycles, see the Élan
1. This is the timing when ROMCS is qualified with MEMR or MEMW, (Bit 2 of the Miscellaneous 5 Register, Index B3h, = 0).
2. This is the timing when ROMCS is configured as an address decode, (Bit 2 of the Miscellaneous 5 Register, Index B3h, = 1).
These timings are based on default wait state settings, set for 3 wait states in bits 4 and 7 of the Command Delay Register, Index
60h, and required initial programming. These timings may be modified via the MMS Memory Wait State 1 Register, Index 62H,
and the Command Delay Register, Index 60H. (See the Élan
#20665. )
For Fast ROMCS (BIOS ROM) accesses, set bit 6 of Miscellaneous 5 Register, Index B3h. Bits 4 and 5 control wait states when
Fast ROMCS is enabled. For 16-bit Fast ROMCS timings with the default wait state settings of 4 wait states, see Table 54. For
more information about
100
Symbol
t11a
t11b
t1a
t1b
t2a
t2b
t3a
t3b
t4a
t4b
t5a
t5b
t10
t12
t13
t14
t15
t6
t7
t8
t9
ROMCS pulse width (read)
ROMCS pulse width (write)
MEMW active to ROMCS active
ROMCS hold from MEMW inactive
RDDATA setup to command inactive
RDDATA hold from command inactive
DBUFOE active from command
DBUFOE hold from MEMW
DBUFOE hold from MEMR
ENDIRH, ENDIRL hold from MEMR
ROMCS hold from SA
SA stable to ROMCS active
SA stable to ROMCS active
SA hold from ROMCS inactive (write)
SA hold from ROMCS inactive (read)
MEMR active to ROMCS active
ROMCS hold from MEMR inactive
WRDATA setup to command inactive
WRDATA hold from command inactive
ENDIRH, ENDIRL setup before MEMR
ROMCS active to command active
Table 52. BIOS ROM Read/Write 8 Bit Cycle (See Figure 41)
Parameter Description
TM
SC300 and Élan
Élan™SC310 Microcontroller Data Sheet
P R E L I M I N A R Y
TM
SC310 Devices’ ISA Bus Anomalies Application Note , order #20747.
TM
SC310 Microcontroller Programmer’s Reference Manual, order
Notes
1
2
1
1
1
1
1
1
1
1
2
2
Min
390
335
200
55
50
40
50
50
–2
–4
65
0
0
0
0
5
Preliminary
Max
50
5
2
1
5
Units
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns