
CHAPTER 7 INITIALIZATION INTERFACE
207
7.3 RESET OF THE CPU CORE
This section describes the reset sequence of the V
R
4100 CPU core. For details about factors of reset or reset of
the whole V
R
4102, refer to 7.1 and Chapter 15.
7.3.1 Cold Reset
In the V
R
4102, a cold reset sequence is executed in the CPU core in the following cases:
x
RTC reset
x
RSTSW reset
x
Deadman’s SW shutdown
x
Software shutdown
x
HAL Timer shutdown
x
Battery low shutdown
x
Battery lock release shutdown
A Cold Reset completely initializes the CPU core, except for the following register bits.
x
The TS and SR bits of the Status register are cleared to 0.
x
The ERL and BEV bits of the Status register are set to 1.
x
The upper limit value (31) is set in the Random register.
x
The Wired register is initialized to 0.
x
Bits 31 to 28 of the Config register are set to 0 and bits 22 to 3 to 0x04800; the other bits are undefined.
x
The values of the other registers are undefined.
Once power to the processor is established, the ColdReset# (internal) and the Reset# (internal) signals are
asserted and a Cold Reset is started. After approximately 2 ms assertion, the ColdReset# signal is deasserted
synchronously with MasterOut. Then the Reset# signal is deasserted synchronously with MasterOut, and the Cold
Reset is completed.
Upon reset, the CPU core becomes bus master and drives the SysAD bus (internal). After Reset# is deasserted,
the CPU core branches to the Reset exception vector and begins executing the reset exception code.