![](http://datasheet.mmic.net.cn/380000/-PD98501_datasheet_16745028/-PD98501_258.png)
CHAPTER 3 SYSTEM CONTROLLER
258
Preliminary User’s Manual S14767EJ1V0UM00
3.5 IBUS Interface Register
3.5.1 ITCNTR (IBUS timeout timer control register)
The IBUS Timeout timer Control Register “ITCNTR” is read-write and word aligned 32bit register. ITCNTR is used
to enable use of the IBUS Timeout Timer. ITCNTR is initialized to 0H at reset and contains the following field:
Bits
Field
Description
0
ITWEN
IBUS Timeout Timer enable
1 = Enable
0 = Disable
31:1
Reserved
Hardwired to 0.
3.5.2 ITSETR (IBUS timeout timer set register)
The IBUS Timeout timer Set Register “ITSETR” is read-write and word aligned 32bit register. ITSET is used to
detect the stall of the IBUS using the bus timer. The IBUS Timeout Timer counts the rising edge of the CPU clock
while the IBUS Frame Signal (ibframe) is asserting. If the bus timer reaches the following ITTIME value, IBUS timer
assert the NMI to CPU when of NER Register is set. The IBUS Timeout value can be set in 1-clock increments in a
range from 1 to 2^32-1 CPU clock. However, the CPU operation is undefined when 0 has been set to ITTIME field.
ITSETR is initialized to 8000_0000H at reset and contains the following fields:
Bits
Field
Description
31:0
ITTIME
IBUS Timeout value setting
Timeout = ITTIME value * system clock period(100MHz:10ns,66MHz:15ns)
example:
ITTIME=05F5E100H (100MHz) or 03F940AAH(66MHz) -> Timeout = 1sec
ITTIME=0BEBC200H(100MHz) or 07F28154H(66MHz) -> Timeout = 2sec
ITTIME=11E1A300H(100MHz) or 0BEBC200H(66MHz) -> Timeout = 3sec
: : :