Interphase Tech 4538 - Manual (Page 29)

Chapter 1: Hardware Description
4538 Hardware Reference Manual 7
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Accesses from the CPM and the PowerSpan cannot go through the Memory
Management Unit (MMU), unlike the core accesses. Therefore, the CPM and
PowerSpan must use the physical addresses when accessing the SDRAMs (most
significant bit = 0). Accesses to 0x8000 0000 will not address the SDRAMs.
Interrupts
The PCI bridge PowerSpan and the communication peripherals generate interrupt requests
to the PowerQUICC II. These interrupts are level sensitive, active low.
Memory Controllers
The sophisticated memory controller units included in the PowerQUICC II are used on the
4538 boards to control all the external devices, except the PowerSpan, which is directly a
60x bus-compatible device. These units are a General Purpose Chip-select Machine
(GPCM) for SRAM, FLASH, and peripherals control, three User Programmable Machines
(UPM), and two SDRAM control machines (one used for Main SDRAM on 4538).
The memory controller unit to be used is defined bank per bank. Each bank is defined by
its Base Register (BRx) and its Option Register (ORx). The memory machine selection is
done in the Option register.
Table 1-2. Local Interrupts
Source MPC2860 Pin MPC8260 IRQ
3RZHU6SDQ LQWHUUXSW $71 ± ,54'3 ± (;7B%* ± ,54
4XDG)$/& ,QWHUUXSW ± ,54'3 ± 7/%,6<1& ± (;7B'%* ± ,54
(WKHUQHW /,8 /;7$ LQWHUUXSW ± ,54'3 ± &.673B287 ± (;7B%5 ± ,54
Table 1-3. PowerQUICC II Memory Controller Machine Usage
Element Accessed Bank Memory Controller
)/$6+ ((3520 [ EXV *3&0
[ EXV 0DLQ PHPRU\ [ EXV 6'5$0 PDFKLQH
4XDG)$/& [ EXV 830$