
2 FEATURES
4
EPSON
S1C38000 TECHNICAL MANUAL
2.8 Programmable Timer
The programmable timer provides five independent 16-bit counters.
2.9 Watchdog Timer
The 16-bit watchdog timer provides a means of system supervision using a down counter which
generates an interrupt or reset when it reaches zero. An output signal from the watchdog timer is also
available for external monitoring and reset circuitry.
2.10 Serial Peripheral Interface (SPI)
Two SPI channels are provided. The first channel is capable of master or slave operation, and
supports a transfer ready input in master mode. The second channel is for master operation only.
2.11 UART / IrDA
Two fully software compatible 16550 UARTs with 16 byte FIFOs each, are provided. The first
channel is a 4-pin UART-only interface that supports RTS and CTS handshaking. The second
channel is either a 2-pin UART or a 3-pin IrDA SIR/FIR (IrDA v1.1). In IrDA mode, a shut down
pin is available for IrDA PHY. SIR supports transfer speeds of 9.6 to 115.2 kbps. Both MIR and FIR
data transfers are not supported. Both UARTs support speeds up to 1.5 Mbps, but do not support a 5-
bit data interface.
Note: The S1C38 peripheral block has some control bits for FIR data transfer and this manual contains
their descriptions, note, however that the S1C38000 does not support both MIR and FIR data
transfers. Be aware that FIR operations are not guaranteed in the S1C38000.
2.12 DMA Controller
The DMA controller supports four internal channels and two external channels. The DMA
controller supports 8/16/32 bit transfer cycles, single or continuous transfer mode, and interrupt at
the end of DMA transfer.
2.13 Interrupt Controller
The Interrupt controller handles two FIQ (Fast Interrupt Request) and 32 IRQ requests. One external
interrupt request input is provided.
2.14 General Purpose I/O (GPIO)
There are 16 dedicated GPIO pins divided into two 8-bit GPIO ports: port A and port B. Each GPIO
port can generate an interrupt. There are also 21 multiplexed GPIO pins, and 13 multiplexed output-
only GPO pins. These additional GPIOs and GPOs do not support the generation of interrupts.
2.15 Clock and Power Management
Two crystal-driven PLLs are provided. The first PLL requires a 32.768 kHz source and the second
PLL requires a 6 MHz source. The 6 MHz clock input is optional to provide accurate USB and FIR
otherwise those clock source is provided by 32.768 kHz PLL. Alternatively, the second PLL source
input can be a 48 MHz clock that bypasses the PLL. The power management module can be
configured to reduce or shutdown the various internal clocks to minimize power consumption.