Motorola MPC823e Reference Manual page 473

Table 16-4. RISC Timer Table Parameter RAM Memory Map
ADDRESS
Timer Base + 00
Timer Base + 02
Timer Base + 04
Timer Base + 06
Timer Base + 08
Timer Base + 0C
NOTE: You are only responsible for initializing the items in bold.
Timer Base = (IMMR & 0xFFFF0000) + 0x3DB0.
• TM_BASE—This index pointer contains a 16-bit offset from the beginning of the
dual-port RAM to the location of your timer table entry. For the timer table entry area,
you must allocate four bytes for each timer used. If you use all 16 timers, you must
allocate 64 bytes in the timer table entry area. If you do not use all the timers, the timers
must always be allocated in ascending order to save space. For example, if you only
need two timers, then 8 bytes are required for the timer table entry area as long as you
only enable RISC timers 0 and 1.
Note: The timer table entry area pointed to by the TM_BASE must always be aligned
to a word boundary that is evenly divisible by four.
• TM_PTR—This index pointer is used exclusively by the RISC microcontroller to point
to the next entry to be executed in the timer table. You must not modify this pointer.
MOTOROLA
NAME WIDTH
TM_BASE Half-word
TM_PTR Half-word
R_TMR Half-word
R_TMV Half-word
TM_CMD Word
TM_CNT Word
MPC823e REFERENCE MANUAL
Communication Processor Module
DESCRIPTION
RISC Timer Table Base Address Index Pointer
RISC Timer Table Pointer
RISC Timer Mode Register
RISC Timer Valid Register
RISC Timer Command Register
RISC Timer Internal Counter
16-19