Datasheet

Chapter 10 XGATE (S12XGATEV3)
MC9S12XE-Family Reference Manual Rev. 1.25
Freescale Semiconductor 363
this register to a channel priority level (non-zero value) selects the corresponding Initial Stack Pointer
Registers XGISP74 or XGISP31 (see Table 10-6).
Read: Anytime
Write: Anytime
10.3.1.5 XGATE Initial Stack Pointer for Interrupt Priorities 7 to 4 (XGISP74)
The XGISP74 register is intended to point to the stack region that is used by XGATE channels of priority
7 to 4. Every time a thread of such priority is started, RISC core register R7 will be initialized with the
content of XGISP74.
Read: Anytime
Write: Only if XGATE requests are disabled (XGE = 0) and idle (XGCHID = $00))
Module Base +0x0005
76543210
R000000
XGISPSEL[1:0]
W
Reset 00000000
= Unimplemented or Reserved
Figure 10-6. XGATE Initial Stack Pointer Select Register (XGISPSEL)
Table 10-5. XGISPSEL Field Descriptions
Field Description
1-0
XGISPSEL[1:0]
Register select— Determines whether XGISP74, XGISP31, or XGVBR is mapped to “Module Base +0x0006”.
See Table 10-6.
Table 10-6. XGISP74, XGISP31, XGVBR Mapping
XGISPSEL[1:0] Register Mapped to “Module Base +0x0006“
3
Reserved
2 XGISP74
1 XGISP31
0 XGVBR
Module Base +0x0006
1514131211109876543210
R
XGISP74[15:1]
0
W
Reset 0000000000000000
= Unimplemented or Reserved
Figure 10-7. XGATE Initial Stack Pointer for Interrupt Priorities 7 to 4 (XGISP74)