ZHCSA13P November 2008 – February 2021 TMS320F28020 , TMS320F280200 , TMS320F28021 , TMS320F28022 , TMS320F28023 , TMS320F28023-Q1 , TMS320F28026 , TMS320F28026-Q1 , TMS320F28026F , TMS320F28027 , TMS320F28027-Q1 , TMS320F28027F , TMS320F28027F-Q1
PRODUCTION DATA
As with many MCU-type devices, multiple buses are used to move data between the memories and peripherals and the CPU. The memory bus architecture contains a program read bus, data read bus, and data write bus. The program read bus consists of 22 address lines and 32 data lines. The data read and write buses consist of 32 address lines and 32 data lines each. The 32-bit-wide data buses enable single cycle 32-bit operations. The multiple bus architecture, commonly termed Harvard Bus, enables the C28x to fetch an instruction, read a data value and write a data value in a single cycle. All peripherals and memories attached to the memory bus prioritize memory accesses. Generally, the priority of memory bus accesses can be summarized as follows:
| Highest: | Data Writes | (Simultaneous data and program writes cannot occur on the memory bus.) | |
| Program Writes | (Simultaneous data and program writes cannot occur on the memory bus.) | ||
| Data Reads | |||
| Program Reads | (Simultaneous program reads and fetches cannot occur on the memory bus.) | ||
| Lowest: | Fetches | (Simultaneous program reads and fetches cannot occur on the memory bus.) |