MC68MH360EM25L Freescale Semiconductor, MC68MH360EM25L Datasheet - Page 336

• Manufacturer Part Number: MC68MH360EM25L
• Description: IC MPU QUICC ETHER 25MHZ 240FQFP
• Manufacturer: Freescale Semiconductor

Specifications of MC68MH360EM25L

• Processor Type: M683xx 32-Bit
• Speed: 25MHz
• Voltage: 5V
• Mounting Type: Surface Mount
• Package / Case: 240-FQFP
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Features: -

RISC Timer Tables
All operations on the RISC timer tables are based on a fundamental "tick" of the RISC inter-
nal timer, which is programmed in the RISC RCCR. The tick is a multiple of 1024 general
system clocks. (See 7.1 RISC Controller for more details.)
The RISC timer tables have the lowest priority of all RISC operations. Therefore, if the RISC
is so busy with other tasks that it does not have time to service the timer during a tick interval,
one or more of the timers may not be updated during a tick.
This behavior can actually be used to estimate the worst-case loading of the RISC proces-
sor. (See Table 7-2 for more details.)
The RISC timer tables are configured in the RCCR, the RISC timer table parameter RAM,
and by the SET TIMER command issued to the CP command register, the RISC timer event
register, and the RISC timer mask register.
7.4.1 RISC Timer Table Parameter RAM
Two areas of internal RAM are used for the RISC timer tables: the RISC timer table param-
eter RAM and RISC timer table entries (see Figure 7-5). The RISC timer table parameter
RAM area begins at the RISC timer base address (see Table 7-2). This area is used for the
general timer parameters.
7-12
• Continuously Updated Reference Counter
ALWAYS THE SAME LOCATION
Figure 7-5. RISC Timer Table RAM Usage
Freescale Semiconductor, Inc.
For More Information On This Product,
CAN BE ANYWHERE IN
THE DUAL-PORT RAM
IN PARAMETER RAM
MC68360 USER’S MANUAL
Go to: www.freescale.com
INTERNAL DUAL-PORT RAM
(UP TO 64 BYTES)
PARAMETER
(14 BYTES)
TM_BASE
ENTRIES
16 RISC
TIMER
TABLE
TIMER
TABLE
RISC
RAM
POINTER
MOTOROLA