Technical data

MVME4100 Single Board Computer Programmer’s Reference (6806800H19B)

3.1.2 System Control Register

The MVME4100 has a System Control Register that provides general board control bits.

BD_TYPE Board Type. These bits indicate the board type.

00: VME SBC

01: PrPMC

10-11: reserved

SAFE_START ENV Safe Start. This bit reflects the current state of the ENV safe start select

switch. A cleared condition indicates that the ENV settings programmed in

NVRAM should be used by the firmware. A set condition indicates that firmware

should use the safe ENV settings.

PCI MODE PCI mode. This bit reflects the current state of the PCI Mode switch. A cleared

condition indicates the switch is off. A set condition indicates the switch is on.

PCI 66 PCI 66. This bit reflects the current state of the PCI 66 switch. A cleared condition

indicates the switch is off. A set condition indicates the switch is on.

MASTER WP MASTER WP. This bit reflects the current state of the MASTER WP switch. A

cleared condition indicates the switch is off. A set condition indicates the switch

is on. When this switch is on, the NOR FLASH, NAND FLASH, MRAM and I2C

EEPROMs are write protected. When this switch is off, NOR FLASH, NAND

FLASH, MRAM and I2C EEPROMs are not write protected by this function. This

switch does not write protect the SPD on the SO-CDIMM. Other switches and

control bits may write protect individual devices.

SW8 SW8. This bit reflects the current state of SW8. A cleared condition indicates the

switch is off. A set condition indicates the switch is on.

Table 3-3 System Control Register

REG System Control Register - 0xF200 0001

BIT76543 2 1 0

Field BRD_RST RSVD RSVD RSVD EEPROM_

RSVD

OPER R/W R R R R/W R

RESET00000 0 1 0