MPC561/MPC563 Reference Manual, Rev. 1.2
Freescale Semiconductor
20-1
Chapter 20
Dual-Port TPU3 RAM (DPTRAM)
The dual-port RAM (DPTRAM) module with TPU3 microcode storage support consists of a control
register block and an 8-Kbyte array of static RAM, which can be used either as a microcode storage for
TPU3 or as a general-purpose memory. The MPC561/MPC563 has one DPTRAM module. The module
serves two TPU3 modules (A and B).
The DPTRAM module acts as a common memory on the IMB3 and allows the transfer of data to the two
TPU3 modules. Therefore, the DPTRAM interface includes an IMB3 bus interface and two TPU3
interfaces. When the DPTRAM is being used in microcode mode, the array is only accessible to the TPU3
via a separate local bus, and not via the IMB3.
In the MPC561/MPC563, the DPTRAM base address register (RAMBAR) must be set to a particular value
to fit into the IMB memory map of the part. The DPTRAM RAMBAR register
must
be programmed to
0xFFA0.
The DPTRAM module is powered by V
DD
in normal operation. The entire array may be used as standby
RAM if standby power is supplied via the IRAMSTBY pin of the MPC561/MPC563. IRAMSTBY must
be supplied by an external source.
The DPTRAM may also be used as the microcode control store for up to two TPU3 modules when placed
in a special emulation mode. In this mode the DPTRAM array may only be accessed by either or both of
the TPU3 units simultaneously via separate emulation buses, and not via the IMB3.
The DPTRAM contains a multiple input signature calculator (MISC) in order to provide RAM data
corruption checking. The MISC reads the DPTRAM address and generates a 32-bit data-dependent
signature. This signature can then be checked by the host.
NOTE
The RCPU cannot perform instruction fetches from any module on the
IMB3 (including the DPTRAM). Only data accesses are permitted.
20.1
Features
•
Eight Kbytes of static RAM
•
Accessible by the CPU only if neither TPU3 is in emulation mode
•
Low-power stop operation
— Entered by setting the STOP bit in the DPTMCR
— Does not enter low-power state while in TPU3 emulation mode for protection
•
TPU3 microcode mode
Summary of Contents for MPC561
Page 84: ...MPC561 MPC563 Reference Manual Rev 1 2 lxxxiv Freescale Semiconductor...
Page 144: ...Signal Descriptions MPC561 MPC563 Reference Manual Rev 1 2 2 46 Freescale Semiconductor...
Page 206: ...Central Processing Unit MPC561 MPC563 Reference Manual Rev 1 2 3 62 Freescale Semiconductor...
Page 302: ...Reset MPC561 MPC563 Reference Manual Rev 1 2 7 14 Freescale Semiconductor...
Page 854: ...Time Processor Unit 3 MPC561 MPC563 Reference Manual Rev 1 2 19 24 Freescale Semiconductor...
Page 968: ...Development Support MPC561 MPC563 Reference Manual Rev 1 2 23 54 Freescale Semiconductor...
Page 1144: ...Internal Memory Map MPC561 MPC563 Reference Manual Rev 1 2 B 34 Freescale Semiconductor...
Page 1212: ...TPU3 ROM Functions MPC561 MPC563 Reference Manual Rev 1 2 D 60 Freescale Semiconductor...
Page 1216: ...Memory Access Timing MPC561 MPC563 Reference Manual Rev 1 2 E 4 Freescale Semiconductor...