36 Bit
RAM
36 Bi t
TCR AMW 2
TCRAMW 1
Cortex-R4F
B0
TCM
B1
TCM
EVEN Address
TCM BUS
64 Bit data
and 8 ECC bits
ODD Address
TCM BUS
64 Bit data
and 8 ECC bits
Upper 32 bits data
and 4 ECC bits
36 bit
Wide
RAM
36 Bit
RAM
36 Bi t
36 bit
Wide
RAM
36 Bit
RAM
36 Bi t
36 bit
Wide
RAM
36 Bit
RAM
36 Bi t
36 bit
Wide
RAM
Lower 32 bits data
and 4 ECC bits
Upper 32 bits data
and 4 ECC bits
Lower 32 bits data
and 4 ECC bits
Overview
306
SPNU503C – March 2018
Copyright © 2018, Texas Instruments Incorporated
Tightly-Coupled RAM (TCRAM) Module
6.1
Overview
The Hercules family of microcontrollers are based on the ARM Cortex-R4F processor. This CPU has two
tightly-coupled memory interfaces – ATCM and BTCM, which are used to interface to the program and
data memories, respectively. The Hercules MCUs use the ATCM interface for the main flash memory and
the BTCM interface for the CPU data RAM.
6.1.1 B0TCM and B1TCM Connection Diagram
The BTCM interface is further divided into two parts – B0TCM and B1TCM, which are both used to
interface to actual RAM banks as shown in
Figure 6-1. TCRAM Module Connections
6.1.2 Main Features
The main features of the tightly-coupled RAM interface module are:
•
Controls read/write accesses to the data RAM
•
Decodes addresses within the memory region allocated for the RAM
•
Supports read and write accesses in 64-bit, 32-bit, 16-bit or 8-bit access sizes
–
Does not support bit-wise operations
•
Safety Features:
–
Support for Cortex-R4F CPU's Built-In Single-Error-Correction Double-Error-Detection (SECDED)
Logic
•
Uses the CPU's Event bus and maintains the SECDED status in memory-mapped registers
•
Captures the number of occurrences of single-bit or multi-bit errors as well as the RAM address
that has the fault
•
Generates signals for indicating single-bit and multi-bit errors to the Error Signaling Module
(ESM)
–
Support for Cortex-R4F CPU's Parity Protection Logic for BTCM Address Bus and Control Signals
•
Uses the CPU's TCM Address Parity Scheme and indicates an address bus parity error to the
ESM