mpc823rg Freescale Semiconductor, Inc, mpc823rg Datasheet - Page 411

• Manufacturer Part Number: mpc823rg
• Description: Mpc823 Powerquicc Integrated Communications Processor For Portable Systems
• Manufacturer: Freescale Semiconductor, Inc

15.5.4.2.2 Chip-Select Signals. The MS field in the base register of the accessed memory
bank selects a user-programmable machine on the currently requested cycle. The selected
UPM only affects the assertion and negation of the appropriate CSx signal and its timing is
specified in the UPM RAM word. Figure 15-28 illustrates how the CSx signals are controlled
by the UPMs.
UPMA
UPMB
GPCM
Note: The UPM refresh is done in a round robin manner. If more than one chip-select
uses the same UPM, the refreshes will progress through each one. For example,
if you have three chip-selects using UPMA, you would need to set the periodic
timer A period to one-third the normal refresh.
Freescale Semiconductor, Inc.
For More Information On This Product,
Figure 15-28. CSx Signal Selection
MPC823 REFERENCE MANUAL
Go to: www.freescale.com
BANK SELECTED
MS[0:1] IN BRx
MUX
SWITCH
MS[0:1]
00
01
10
11
MACHINE
Memory Controller
GPCM
UPMA
UPMB
—
CS0
CS1
CS2
CS3
CS4
CS5
CS6
CS7
15-55