Mitel MT90840 manual AB11 AB10

MT90840 Preliminary Information

Receive Path Connection Memory High (RPCM High) - This is a 7-bit x 512-position memory. Used only in TM1, 2, & 3.

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MC

DC

OE

AB11 AB10

AB9

AB8

(RX Path CM High)

7 6 5 4 3 2 1 0

MC Message Channel: The message channel contents are provided by the CPU in bits AB0-7 in the Rx Path Connection Memory Low. If MC is HIGH, the contents of the corresponding location of RPCM Low are output on this serial port channel. If MC is LOW, the contents of the corresponding location in RPCM Low act as an address for the Rx Path Data Memory and so determine the source of the connection (input channels from the PDi0-7 port).

DC Direction Control: DC set HIGH indicates this channel is an output. DC set LOW indicates this channel is an input. The operation of this bit is modified by the state of FDC in the IMS Register.

When FDC = LOW (2.048, 4.096 or 8.192 Mbps) the 512 DC bits (256 at 2.048) each define the direction of a pair of pins for each channel. When DC is set LOW the associated channel on the STo pin becomes an input, and the corresponding channel on the same-number STi pin is automatically used as the output for this time slot. When DC is set HIGH, STo is the output, and STi is the input for this time slot (default).

When FDC = HIGH (2.048 Mbps), the 512 DC bits can be used to control the direction of each individual 64 kbps time slot present on the 16 serial I/O lines on a non-symmetrical basis; i.e. all 512 channels can be configured as outputs or inputs or any mixed combination. If DC is LOW, this serial port channel is defined as input. If DC is HIGH, this channel is defined as output. Note that the CPU still has to set OE to enable the output buffers on each channel defined as an output.

OE Output Enable. Per-channel tristate control for each channel on the serial port side. If FDC is HIGH, the 512 OE bits enable the output for each of the 512 ST channels, unless the channel is defined as an input by the DC bit. In 4.096 and 8.192 Mbps modes, the OE bit enables the output buffer either on a STo pin, or an STi pin, as defined by the accompanying DC bit.

AB8-11Source Channel Address. These 4 bits are used along with AB0-7 to select any of the 2430 parallel incoming channels from the parallel port and determine the switch connection to the 512 possible destination channels on the serial port.

Receive Path Connection Memory Low (RPCM Low) - This is an 8-bit x 512-position memory. Used only in TM1, 2 &3.

AB7

AB6

AB5

AB4

AB3

AB2

AB1

AB0

(RX Path CM Low)

7 6 5 4 3 2 1 0

AB0-7Source Channel Address. In switching mode (MC=LOW), these 8 bits are used along with AB8-11 to select one of the 2430 incoming channels from the parallel port. In message mode (MC=HIGH), these 8 bits are programmed by the CPU with the message patterns desired on the corresponding serial output channel.

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