Registers

R

Table 1-13:Branch Target Register (BTR)

Bits

Name

Description

Reset Value

 

 

 

 

0:31

BTR

Branch target address used by handler

0x00000000

 

 

when returning from an exception

 

 

 

caused by an instruction in a delay slot

 

 

 

Read-only

 

 

 

 

 

Floating Point Status Register (FSR)

The Floating Point Status Register contains status bits for the floating point unit. It can be read with an MFS, and written with an MTS instruction. When read or written, the register is specified by setting Sa = 0x0007.

RESERVED

27 28 29 30 31

↑ ↑ ↑ ↑ ↑

IO DZ OF UF DO

Figure 1-8: FSR

Table 1-14:Floating Point Status Register (FSR)

Bits

Name

Description

Reset Value

 

 

 

 

0:26

Reserved

 

undefined

 

 

 

 

27

IO

Invalid operation

0

 

 

 

 

28

DZ

Divide-by-zero

0

 

 

 

 

29

OF

Overflow

0

 

 

 

 

30

UF

Underflow

0

 

 

 

 

31

DO

Denormalized operand error

0

 

 

 

 

Processor Version Register (PVR)

The Processor Version Register is controlled by the C_PVR configuration option on

MicroBlaze. When C_PVR is set to 0 the processor does not implement any PVR and

MSR[PVR]=0. If C_PVR is set to 1 then MicroBlaze implements only the first register:

PVR0, and if set to 2 all 12 PVR registers (PVR0 to PVR11) are implemented.

When read with the MFS instruction the PVR is specified by setting Sa = 0x200x, with x being the register number between 0x0 and 0xB.

MicroBlaze Processor Reference Guide

www.xilinx.com

27

UG081 (v6.0) June 1, 2006

1-800-255-7778

 

Page 27
Image 27
Xilinx EDK 8.2i manual Floating Point Status Register FSR, Processor Version Register PVR