Network Router User Manual

TMS380C26
NETWORK COMMPROCESSOR
SPWS010A–APRIL 1992–REVISED MARCH 1993
POST OFFICE BOX 1443 • HOUSTON, TEXAS
77251–1443
73
PARAMETER MEASUREMENT INFORMATION
80x8x mode bus arbitration timing, SIF returns control
NO. PARAMETER MIN MAX UNIT
220
†
Delay from SBCLK low in I1 cycle to SADH0–SADH7, SADL0–SADL7, SPL, SPH, SRD, and SWR
high-impedance
35 ns
223b
†
Delay from SBCLK low in I1 cycle to SBHE high-impedance 45 ns
224b Delay from SBCLK low in cycle I2 to SOWN high 25 ns
224d Delay from SBCLK low in cycle I2 to SDDIR high 30 ns
230 Delay from SBCLK high in cycle I1 to SHRQ low 25 ns
240
†
Setup of SRD, SWR, and SBHE high-impedance before SOWN no longer low 0 ns
†
This specification has been characterized to meet stated value.
READ
WRITE
SIF
SIF
SOWN
(see Note B)
SDDIR
SADH0–SADH7,
SADL0–SADL7,
SPH, SPL
SBHE
SRD, SWR
SHRQ
(see Note A)
SIF Outputs:
SHLDA
SBCLK
User MasterBus ExchangeSIF Master
(T2)(T1)I2I1T4T3
224d
220
240
223b
240
220
HI-Z
HI-Z
HI-Z
224b
230
NOTES: A. In 80x8x mode, the system interface deasserts SHRQ on the rising edge of SBCLK following the T4 state of the last system bus
transfer it controls. In 68xxx mode, the system interface deasserts SBRQ on the rising edge of SBCLK in state T2 of the first system
bus transfer it controls.
B. While the system interface DMA controls are active (i.e., SOWN
is asserted), the SCS input is disabled.
Figure 35. 80x8x Mode Bus Arbitration Timing, SIF Returns Control