Functional Description and Application Information
Die-to-Die Initiator (D2DIV1)
MM912F634
Freescale Semiconductor
302
Clock halt on system STOP
Configurable for 4- or 8-bit wide transfers
Configurable timeout period
Non-maskable interrupt on transaction errors
Transaction Status and Error Flags
Interrupt enable for receiving interrupt (from D2D target)
4.37.1.3
Modes of Operation
4.37.1.3.1
D2DI in STOP/WAIT Mode
The D2DI stops working in STOP/WAIT mode. The D2DCLK signal as well as the data signals used are driven low (only after the
end of the current high phase, as defined by D2DCLKDIV).
Waking from STOP/WAIT mode, the D2DCLK line starts clocking again and the data lines will be driven low until the first
transaction starts.
STOP and WAIT mode are entered by different CPU instructions. In the WAIT mode, the behavior of the D2DI can be configured
(D2DSWAI). Every (enabled) interrupt can be used to leave the STOP and WAIT mode.
4.37.1.3.2
D2DI in special modes
The MCU can enter a special mode (used for test and debugging purposes as well as programming the FLASH). In the D2DI the
“write-once” feature is disabled. See the MCU description for details.
4.37.2
External Signal Description
The D2DI optionally uses 6 or 10 port pins. The functions of those pins depends on the settings in the D2DCTL0 register, when
the D2DI module is enabled.
4.37.2.1
D2DCLK
NOTE
The maximum allowed D2D target frequency (fD2D) might be lower than the maximum
initiator frequency.
When the D2DI is enabled this pin is the clock output. This signal is low if the initiator is disabled, in STOP mode or in WAIT mode
(with D2DSWAI asserted), otherwise it is a continuos clock. This pin may be shared with general purpose functionality if the D2DI
is disabled.
4.37.2.2
D2DDAT[7:4]
When the D2DI is enabled and the interface connection width D2DCW is set to be 8-bit wide, those lines carry the data bits 7:4
acting as outputs or inputs. When they act as inputs pull-down elements are enabled. If the D2DI is disabled or if the interface
connection width is set as 4-bit wide, the pins may be shared with general purpose pin functionality.
4.37.2.3
D2DDAT[3:0]
When the D2DI is enabled those lines carry the data bits 3:0 acting as outputs or inputs. When they act as inputs pull-down
elements are enabled. If the D2DI is disabled the pins and may be shared with general purpose pin functionality.
4.37.2.4
D2DINT
The D2DINT is an active input interrupt input driven by the target device. The pin has an active pull-down device. If the D2DI is
disabled, the pin may be shared with general purpose pin functionality.