LSI Logic Confidential
Cycle Types
10-7
Copyright © 2001, 2002 by LSI Logic Corporation. All rights reserved.
10.4.3 Timing Parameters
Several parameters can be used to extend the cycle length by adding
delays in particular places. These delays are specified in internal clock
period units.
The timing parameters for the basic cycle are illustrated in Figures
and
, with a description of their function in
below.
Table 10.2
Timing Parameters
Parameters
Range of
Values
Description
CSO
0–15
Delay from M_A and M_RD/WR driven to fall of M_CS. For write cycles,
Data is driven out along with fall of M_CS.
DSO
0–15
Delay from Addr and M_RD/WR driven to fall of data strobes (M_UDS and
M_LDS or M_OE, M_UWE and M_LWE).
DT
0–127
For self-timed accesses, delay from M_A and M_RD/WR driven to
M_DTACK asserted or M_WAIT deasserted. For self-timed accesses,
M_DTACK is pulsed low for one clock, then brought high for one clock
before being 3-stated whereas M_WAIT is driven LOW at the start of the
cycle then brought HIGH for one clock before being 3-stated. On a read
cycle, data is latched in at the clock cycle after M_DTACK is asserted or
M_WAIT deasserted. For device-paced M_DTACK transfers, see
10.4.5, “Device-Paced Transfers,” page 10-8
For device-paced M_WAIT transfers, this value indicates the amount of time
to wait before sampling the M_WAIT pin for cycle completion. For more
information, see
Section 10.4.5, “Device-Paced Transfers,” page 10-8
BDT
0–15
For self-timed burst accesses, delay from end of the previous data transfer
phase to assertion of M_DTACK or deassertion of M_WAIT for the next
phase. For device-paced transfers, see
BH
0–15
Added delay from end of cycle (M_CS and data strobes deasserted) to start
of next cycle. During the BH time, Addr and M_RD/WR are held stable and
all other signals are held inactive. On a write cycle, the Data bus is also
driven with the write data for the BH time.
AS
0–3
Multiplexed address set up time from address and M_ALE asserted to fall
of M_ALE.
AH
0–1
Multiplexed address hold time from fall of M_ALE to Addr/Data change.
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