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Chapter 10 XGATE (S12XGATEV3)
MC9S12XE-Family Reference Manual Rev. 1.07
Freescale Semiconductor
365
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))
10.3.1.6
XGATE Initial Stack Pointer for Interrupt Priorities 3 to 1 (XGISP31)
The XGISP31 register is intended to point to the stack region that is used by XGATE channels of priority
3 to 1. Every time a thread of such priority is started, RISC core register R7 will be initialized with the
content of XGISP31.
Read: Anytime
Write: Only if XGATE requests are disabled (XGE = 0) and idle (XGCHID = $00))
Module Base +0x0006
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
0
R
W
XGISP74[15:1]
Reset
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
= Unimplemented or Reserved
Figure 10-7. XGATE Initial Stack Pointer for Interrupt Priorities 7 to 4 (XGISP74)
Table 10-6. XGISP74 Field Descriptions
Field
Description
15–1
XBISP74[15:1]
Initial Stack Pointer
— The XGISP74 register holds the initial value of RISC core register R7, for threads of
priority 7 to 4.
Module Base +0x0006
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
0
R
W
XGISP31[15:1]
Reset
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
= Unimplemented or Reserved
Figure 10-8. XGATE Initial Stack Pointer for Interrupt Priorities 3 to 1 (XGISP31)
Table 10-7. XGISP31 Field Descriptions
Field
Description
15–1
XBISP31[15:1]
Initial Stack Pointer
— The XGISP31 register holds the initial value of RISC core register R7, for threads of
priority 3 to 1.