Ricoh R5C841 - Manual (Page 51)

R5C841 PCI-CardBus/IEEE 1394/SD Card/Memory Stick/xD/ExpressCard Data Sheet
12345  2004 R EV .1.10 4-26
4.22.7 Reference Voltage Circuit and Reference Current Circuit
The PHY block of R5C841 supports terminals of the external parts for the Reference voltage
circuit and the Reference current circuit. Each terminal should be connected to indicated
capacitors and resistors.
Reference Voltage Circuit Reference Current Circuit
R5C841 R5C841
VREF REXT
0.01uF 10kohm
±1%
AGND AGND
4.23 Function’s Selection
The R5C841 can make each function disable by UDIO3, UDIO4 and VPPEN0. Setting UDIO3 to
pull-down disables the SD Card interface, setting UDIO4 to pull-down disables the Memory Stick
interface, and setting VPPEN0 to pull-down disables the xD Picture Card interface. Disabled
function cannot detect the corresponding configuration register. (Master Aborts) The function’s
selection is as follows.
On use of the Serial ROM, set the Serial ROM in order to disable each function, because UDIO3,
UIDO4 and VPPEN0 are set to only pull-up.
Function No.
UDIO3 UDIO4 VPPEN0 SD MS xD
0 1 2 3 4
Pull-up Pull-up Pull-up Enable Enable Enable PCCard 1394 SD MS xD
Pull-down Pull-up Pull-up Disable Enable Enable PCCard 1394 MS xD –
Pull-up Pull-down Pull-up Enable Disable Enable PCCard 1394 SD xD –
Pull-down Pull-down Pull-up Disable Disable Enable PCCard 1394 xD – –
Pull-up Pull-up Pull-down Enable Enable Disable PCCard 1394 SD MS –
Pull-down Pull-up Pull-down Disable Enable Disable PCCard 1394 MS – –
Pull-up Pull-down Pull-down Enable Disable Disable PCCard 1394 SD – –
Pull-down Pull-down Pull-down Disable Disable Disable PCCard 1394 – – –