Freescale Semiconductor MCF54455 Reference Manual page 72

• 8-bit condition code register (CCR)
• EMAC registers
— Four 48-bit accumulator registers partitioned as follows:
– Four 32-bit accumulators (ACC0–ACC3)
– Eight 8-bit accumulator extension bytes (two per accumulator). These are grouped into two
32-bit values for load and store operations (ACCEXT01 and ACCEXT23).
Accumulators and extension bytes can be loaded, copied, and stored; results from EMAC
arithmetic operations generally affect the entire 48-bit destination.
— One 16-bit mask register (MASK)
— One 32-bit Status register (MACSR) including four indicator bits signaling product or
accumulation overflow (one for each accumulator: PAV0–PAV3)
The supervisor programming model is to be used only by system control software to implement restricted
operating system functions, I/O control, and memory management. All accesses that affect the control
features of ColdFire processors are in the supervisor programming model, that consists of registers
available in user mode as well as the following control registers:
• 16-bit status register (SR)
• 32-bit supervisor stack pointer (SSP)
• 32-bit vector base register (VBR)
• 32-bit cache control register (CACR)
• 32-bit access control registers (ACR0, ACR1, ... ACR3)
• One 32-bit memory base address register (RAMBAR)
• 32-bit address space ID register (ASID)
• 32-bit MMU base address register (MMUBAR)
1
BDM
Load: 0x080 Data Register 0 (D0)
Store: 0x180
Load: 0x081 Data Register 1 (D1)
Store: 0x181
Load: 0x082–7 Data Register 2–7 (D2–D7)
Store: 0x182–7
Load: 0x088–8E Address Register 0–6 (A0–A6)
Store: 0x188–8E
Load: 0x08F Supervisor/User A7 Stack Pointer (A7)
Store: 0x18F
0x804 MAC Status Register (MACSR)
Freescale Semiconductor
(described fully in Chapter 5, "Enhanced Multiply-Accumulate Unit (EMAC
Table 3-1. ColdFire Core Programming Model
Register
Supervisor/User Access Registers
Width
Access Reset Value
(bits)
32 R/W 0xCF42_602B
32 R/W 0x0600_2670
32 R/W Undefined
32 R/W Undefined
32 R/W Undefined
32 R/W 0x0000_0000
ColdFire Core
Written with
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