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ManualsBrandsMICROCHIP TECHNOLOGY ManualsMicrocontrollers, Microprocessors & QuartzesEmbedded microcontroller CBGA 100 (9x9) 8/16-Bit 32 MHz I/O number 53
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XMEGA B [DATASHEET]
8291B–AVR–01/2013
3.14.6 EIND – Extended Indirect register
This register is concatenated with the Z-register for enabling extended indirect jump (EIJMP) and call (EICALL) to the
whole program memory space on devices with more than 128KB of program memory. The register should be used for
jumps to addresses below 128KB if ECALL/EIJMP are used, and it will not be used if CALL and IJMP commands are
used. For jump or call to addresses below 128KB, this register is not used. This register is not available if the program
memory in the device is less than 128KB.
Bit 7:0 – EIND[7:0]: Extended Indirect Address bits
These bits hold the MSB of the 24-bit address created by EIND and the 16-bit Z-register. Only the number of bits
required to access the available program memory is implemented for each device. Unused bits will always read as zero.
3.14.7 SPL – Stack Pointer Register Low
The SPH and SPL register pair represent the 16-bit SP value. The SP holds the stack pointer that points to the top of the
stack. After reset, the stack pointer points to the highest internal SRAM address. To prevent corruption when updating
the stack pointer from software, a write to SPL will automatically disable interrupts for the next four instructions or until
the next I/O memory write.
Only the number of bits required to address the available data memory, including external memory, up to 64KB is
implemented for each device. Unused bits will always read as zero.
Note: 1. Refer to specific device datasheets for exact initial values.
Bit 7:0 – SP[7:0]: Stack Pointer Register Low
These bits hold the LSB of the 16-bit stack pointer (SP).
3.14.8 SPH – Stack Pointer Register High
Note: 1. Refer to specific device datasheets for exact initial values.
Bit 7:0 – SP[15:8]: Stack Pointer Register High
These bits hold the MSB of the 16-bit stack pointer (SP).
Bit 76543210
+0x0C EIND[7:0]
Read/Write R/W R/W R/W R/W R/W R/W R/W R/W
Initial Value 0 0 0 0 0 0 0 0
Bit 76543210
+0x0D SP[7:0]
Read/Write R/W R/W R/W R/W R/W R/W R/W R/W
Initial Value
(1)
0/1 0/1 0/1 0/1 0/1 0/1 0/1 0/1
Bit 76543210
+0x0E SP[15:8]
Read/Write R/W R/W R/W R/W R/W R/W R/W R/W
Initial Value
(1)
0/1 0/1 0/1 0/1 0/1 0/1 0/1 0/1