There are several memories, digital peripherals, and analog peripherals that can be accessed by both the Master and Control Subsystems. They are grouped into Shared Resources and the Analog Subsystem.
The Shared Resources include the EPI, IPC registers, MTOC Message RAM, CTOM Message RAM, and eight individually configurable Shared RAM blocks. The RAMs of the Shared Resources block have Parity Error Checking.
The Message RAMs and the Shared RAMs can be accessed by the Cortex-M3 CPU and µDMA. The MTOC Message RAM is intended for sending data from the Master Subsystem to the Control Subsystem, having R/W access for the Cortex-M3/µDMA and read-only access for the C28x/DMA. The CTOM Message RAM is intended for sending data from the Control Subsystem to the Master Subsystem, having R/W access for the C28x/DMA and read-only access for the Cortex-M3/µDMA.
The IPC registers provide up to 32 handshaking channels to coordinate the transfer of data through the Message RAMs by polling. Four of these channels are also backed up by four interrupts to PIE on the Control Subsystem side, and four interrupts to the NVIC on the Master Subsystem side (to reduce delays associated with polling).
The eight Shared RAM blocks are similar to the Message RAMs, in that the data flow is only one way; however, the direction of the data flow can be individually set for each block to be from Master to Control Subsystem or from Control to Master Subsystem.
The Analog Subsystem has ADC1, ADC2, and Analog Comparator peripherals that can be accessed through the Analog Common Interface Bus. The ADC Result Registers are accessible by CPUs and DMAs of the Master and Control Subsystems. All other Analog Peripheral Registers are accessible by the C28x CPU only. The Cortex-M3 CPU accesses the ACIB through the System Bus, and the µDMA through the µDMA Bus. The ACIB arbitrates for access to the ADC and Analog Comparator registers between CPU/DMA bus cycles of the Master Subsystem with those of the Control Subsystem. In addition to managing bus cycles, the ACIB also transfers End-of-Conversion ADC interrupts to the Master Subsystem (as well as to the Control Subsystem). The eight EOC sources from ADC1 and the eight EOC sources from ADC2 are AND-ed together by the ACIB, with the resulting eight ADC interrupts going to destinations in both the Master Subsystem and the Control Subsystem.
See Section 5.10 for more information on shared resources and analog peripherals.