TC1796
System Units (Vol. 1 of 2)
Program Memory Unit
User’s Manual 7-2 V2.0, 2007-07
PMU, V2.0
7.2 Program & Data Flash Memory
The embedded Flash module of TC1796 incorporates a 2 Mbyte Flash memory for
program code or constant data (called PFLASH or program Flash) and a 128 Kbyte
Flash memory used for data storage (called DFLASH or data Flash).
Both, PFLASH and DFLASH, provide error correction of single-bit errors within a 64-bit
read double-word, resulting in a very low failure rate. The programming quantity is one
page, including 256 byte for the PFLASH and 128 byte for the DFLASH.
The PFLASH is implemented as one Flash bank. The DFLASH is built up by two Flash
banks. This bank configuration allows combinations of concurrent Flash operations:
• Reading code or data from PFLASH while one bank of the DFLASH is busy with a
program or erase operation.
• Reading data from one bank of the DFLASH while the other bank of the DFLASH is
busy with a program or erase operation.
• Programming one bank of the DFLASH while the other bank of the DFLASH is busy
with an erase operation and simultaneously reading from PFLASH.
Note: It is not possible to read data from DFLASH while the PFLASH is busy with a
program or erase operation.
The embedded Flash module is divided into the following two sub-modules:
• The Flash Interface and Control Module (FIM)
– Controls the execution of Flash commands (Flash command state machine FCS)
– Handles error correction and ECC generation
– Provides a PLMB bus interface to the PMI for instruction accesses and to the DMI
module (via the LMI-Bridge) for data accesses.
• The Flash Array Module (FAM)
– One PFLASH bank of 2 Mbyte
– Two PFLASH banks of 64 Kbyte each
– Control logic that includes assembly buffers and voltage generators, for example
The FIM and FAM are main parts of the Program Memory Unit (PMU). An overview of
the PMU integration into the system architecture is shown in the TC1796 block and bus
system diagrams (see Page 1-9 and Page 6-1). A basic diagram of the Flash modules
is shown in Figure 7-2.
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