ds21ft40 Maxim Integrated Products, Inc., ds21ft40 Datasheet - Page 18

• Manufacturer Part Number: ds21ft40
• Description: Ds21ft40 Four X Three 12 Channel E1 Framer
• Manufacturer: Maxim Integrated Products, Inc.

PARALLEL CONTROL PORT PINS
Signal Name:
Signal Description:
Signal Type:
Flags host controller during conditions and change of conditions defined in the Status Registers 1 and 2
and the FDL Status Register. Active low, open drain output.
Signal Name:
Signal Description:
Signal Type:
Set low to select non–multiplexed bus operation. Set high to select multiplexed bus operation.
Signal Name:
Signal Description:
Signal Type:
In non–multiplexed bus operation (MUX = 0), serves as the data bus. In multiplexed bus operation
(MUX = 1), serves as a 8–bit multiplexed address / data bus.
Signal Name:
Signal Description:
Signal Type:
In non–multiplexed bus operation (MUX = 0), serves as the address bus. In multiplexed bus operation
(MUX = 1), these pins are not used and should be tied low.
Signal Name:
Signal Description:
Signal Type:
In non–multiplexed bus operation (MUX = 0), serves as address bit 6. In multiplexed bus operation
(MUX = 1), serves to demultiplex the bus on a positive–going edge.
Signal Name:
Signal Description:
Signal Type:
Strap high to select Motorola bus timing; strap low to select Intel bus timing. This pin controls the
function of the RD*(DS*), ALE(AS), and WR*(R/W*) pins. If BTS = 1, then these pins assume the
function listed in parenthesis ().
Signal Name:
Signal Description:
Signal Type:
RD* is an active low signal and DS is an active high signal.
Signal Name:
Signal Description:
Signal Type:
Selects which of the four framers is to be accessed for a specific DS21Q44 die.
INT*
Interrupt
Output
MUX
Bus Operation
Input
D0 TO D7 / AD0 TO AD7
Data Bus or Address/Data Bus
Input /Output
A0 TO A5, A7
Address Bus
Input
ALE (AS) / A6
Address Latch Enable (Address Strobe) or A6
Input
BTS
Bus Type Select
Input
RD* (DS)
Read Input (Data Strobe)
Input
FS0 AND FS1
Framer Selects
Input
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DS21FT40