DS3134
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Signal Name:
Signal Description:
Signal Type:
This active low signal is sampled on the rising edge of LCLK to determine when a bus transaction is
complete. This signal is only examined when a bus transaction is taking place. This signal is ignored
when the Local Bus is in the Configuration Mode (LMS = 1) and should be tied high.
LRDY*
Local Bus PCI Bridge Ready [PCI Bridge Mode Only]
Input
Signal Name:
Signal Description:
Signal Type:
This input signal is sampled on the rising edge of LCLK to determine when the device has been granted
access to the bus. In Intel Mode (LIM = 0) this is an active high signal and in Motorola Mode (LIM = 1)
this is an active low signal. This signal is ignored and should be tied high when the Local Bus is in the
Configuration Mode (LMS = 1). Also, in the PCI Bridge Mode (LMS = 0), this signal should be tied
deasserted when the Local Bus Arbitration is disabled via the Local Bus Bridge Mode Control Register.
LHLDA (LBG*)
Local Bus Hold Acknowledge (Local Bus Grant) [PCI Bridge Mode Only]
Input
Signal Name:
Signal Description:
Signal Type:
This active low signal will be asserted when the Local Bus is attempting to take control of the bus. It will
be deasserted in the Intel Mode (LIM = 0) when the bus access is complete. It will be deasserted in the
Motorola Mode (LIM = 1) when the Local Bus Hold Acknowledge/Grant signal (LHLDA/LBG*) has
been detected. This signal is tri-stated when the Local Bus is in the Configuration Mode (LMS = 1) and
in the PCI Bridge Mode (LMS = 0) when the Local Bus Arbitration is disabled via the Local Bus Bridge
Mode Control Register.
LHOLD (LBR*)
Local Bus Hold (Local Bus Request) [PCI Bridge Mode Only]
Output
Signal Name:
Signal Description:
Signal Type:
This active low signal is asserted when the Local Bus Hold Acknowledge/Bus Grant signal
(LHLDA/LBG*) has been detected and it continues it's assertion for a programmable (32 to 1048576)
number of LCLKs based upon the Local Bus Arbitration Timer setting in the Local Bus Bridge Mode
Control Register (LBBMC) register. This signal is tri-stated when the Local Bus is in the Configuration
Mode (LMS = 1).
LBGACK*
Local Bus Grant Acknowledge [PCI Bridge Mode Only]
Output (tri-state capable)
Signal Name:
Signal Description:
Signal Type:
This active low output signal is asserted when all 16-bits of the data bus (LD[15:0]) are active. It will
remain high if only the lower 8-bits (LD[7:0)] is active. If bus arbitration is enabled via the Local Bus
Arbitration (LARBE) control bit in the Local Bus Bridge Mode Control Register (LBBMC), then this
signal will be tri-stated when the Local Bus is not currently involved in a bus transaction and driven when
a bus transaction is active. When bus arbitration is disabled, this signal is always driven. This signal will
remain in tri-state when the Local Bus is not currently involved in a bus transaction and when the Local
Bus is in the Configuration Mode (LMS = 1).
LBHE*
Local Bus Byte High Enable [PCI Bridge Mode Only]
Output (tri-state capable)