![](http://datasheet.mmic.net.cn/370000/P9S12XEP100J1VVLR_datasheet_16728329/P9S12XEP100J1VVLR_190.png)
Chapter 3 Memory Mapping Control (S12XMMCV4)
MC9S12XE-Family Reference Manual , Rev. 1.07
190
Freescale Semiconductor
Table 3-6
shows the address boundaries of each chip select and the relationship with the implemented
resources (internal) parameters.
Table 3-6. Global Chip Selects Memory Space
Table 3-5. MMCCTL0 Field Descriptions
Field
Description
7–6
CS3E[1:0]
Chip Select 3 Enables
— These bits enable the external chip select CS3 output which is asserted during
accesses to specific external addresses. The associated global address range is shown in
Table 3-6
and
Figure 3-17
.
Chip select 3 is only active if enabled in Normal Expanded mode, Emulation Expanded mode.
The function disabled in all other operating modes.
00
Chip select 3 is disabled
01,10,11 Chip select 3 is enabled
5–4
CS2E[1:0]
Chip Select 2 Enables
— These bits enable the external chip select CS2 output which is asserted during
accesses to specific external addresses. The associated global address range is shown in
Table 3-6
and
Figure 3-17
.
Chip select 2 is only active if enabled in Normal Expanded mode, Emulation Expanded mode.
The function disabled in all other operating modes.
00
Chip select 2 is disabled
01,10,11 Chip select 2 is enabled
3–2
CS1E[1:0]
Chip Select 1 Enables
— These bits enable the external chip select CS1 output which is asserted during
accesses to specific external addresses. The associated global address range is shown in
Table 3-6
and
Figure 3-17
.
Chip select 1 is only active if enabled in Normal Expanded mode, Emulation Expanded mode.
The function disabled in all other operating modes.
00
Chip select 1 is disabled
01,10,11 Chip select 1 is enabled
1–0
CS0E[1:0]
Chip Select 0 Enables
— These bits enable the external chip select CS0 output which is asserted during
accesses to specific external addresses. The associated global address range is shown in
Table 3-6
and
Figure 3-17
.
Chip select 0 is only active if enabled in Normal Expanded mode, Emulation Expanded mode.
The function disabled in all other operating modes.
00
Chip select 0 is disabled
01,10,11 Chip select 0 is enabled
Chip Selects
Bottom Address
Top Address
CS3
CS2
2
0x00_0800
0x0F_FFFF minus RAMSIZE
1
1
External RPAGE accesses in (NX, EX)
2
WhenROMHMisset(seeROMHMin
Table 3-15
)theCS2isasserted inthespaceoccupiedbythison-chip
memory block.
3
When the internal NVM is enabled (see ROMON in
Section 3.3.2.5, “MMC Control Register (MMCCTL1)
)
the CS0 is not asserted in the space occupied by this on-chip memory block.
4
External PPAGE accesses in (NX, EX)
0x14_0000
0x1F_FFFF
CS1
CS0
3
0x20_0000
0x3F_FFFF
0x40_0000
0x7F_FFFF minus FLASHSIZE
4