SA-1100 Developer’s Manual 2-5

Functional Description
L_FCLK OCZ LCD frame clock.
L_LCLK OCZ LCD line clock.
L_PCLK OCZ LCD pixel clock.
L_BIAS OCZ LCD ac bias drive.
TXD_C OCZ CODEC transmit.
RXD_C IC CODEC receive.
SCLK_C OCZ CODEC clock.
SFRM_C OCZ CODEC frame signal.
UDC+ OCZ Serial port zero transmit pin (UDC).
UDC- IC Serial port zero r eceive pin (UDC).
TXD_1 OCZ Serial port one transmit pin (SDLC).
RXD_1 IC Serial port one receive pin (SDLC).
TXD_2 OCZ Serial port two transmit pin (IrDA).
RXD_2 IC Serial port two receive pin (IrDA).
TXD_3 OCZ Serial port three transmit pin (UART).
RXD_3 IC Serial port three receive pin (UART).
GP<27:0> ICOCZ General-purpose input output.
ROM_SEL IC ROM select. This pin is used to configure the ROM width. It is either grounded or
pulled high. If ROM_SEL is grounded, the ROM width is 16 bits. If ROM_SEL is
pulled up, the ROM width is 32 bits.
PXTAL IC Input connection for 3.686-MHz crystal.
PEXTAL OCZ Output connection for 3.686-MHz crystal.
TXTAL IC Input connection for 32.768-kHz crystal.
TEXTAL OCZ Output connection for 32.768-kHz crystal.
PWR_EN OCZ Power enable. Active high. PWR_EN enables the external power supply.
Negating it signals the power supply that the system is going into sleep mode and
that the VDD power supply should be removed.
BATT_FAULT IC Battery fault. Signals the SA-1100 that the main power source is going away
(battery is low or has been removed from the system). The assertion of
BATT_FAULT causes the SA-1100 to enter sleep mode. The SA-1100 will not
recognize a wake-up event while this signal is asserted.
VDD_FAULT IC VDD fault. Signals the SA-1100 that the main power supply is going out of
regulation (shorted card is inserted). VDD_FAULT will cause the SA-1100 to enter
sleep mode. VDD_FAULT is ignored after a wake-up event until the poser supply
timer completes (approximately 10 ms).
nRESET IC Hard reset. This active low signal is a lev el-sensitive input used to start the
processor from a known address. A low level will cause the current instruction to
terminate abnormally, and the on-chip caches, MMU, and write buffer to be
disabled.
When nRESET is driven high, the processor will restart from address 0. nRESET
must remain low until the power supply is stable and the internal 3.686-MHz
oscillator has come up to speed. While nRESET is low, the processor will perform
idle cycles.
Table 2-1. Signal Descriptions (Sheet 2 of 3)
Name Type Description