Texas Instruments MSC1210 manual SFR Definitions

SFR Definitions

TMOD (Timer Mode, Address 89H): This SFR is used to configure the mode of operation of each of the two timers. Using this SFR, the program may config- ure each timer to be a 16-bit timer, an 8-bit auto-reload timer, a 13-bit timer, or two separate timers. Additionally, the timers may be configured to only count when an external pin is activated or to count events that are indicated on an external pin.

TL0/TH0 (Timer 0 Low/High, Addresses 8AH/8BH): These two SFRs, taken together, represent timer 0. Their exact behavior depends on how the timer is configured in the TMOD SFR, however, these timers always count up. How and when they increment in value is configurable.

TL1/TH1 (Timer 1 Low/High, Addresses 8CH/8DH): These two SFRs, taken together, represent timer 1. Their exact behavior depends on how the timer is configured in the TMOD SFR, however, these timers always count up. How and when they increment in value is configurable.

CKCON (Clock Control, Address 8EH): This SFR is used by the MSC1210 to provide you with a number of timing controls that allow the MSC1210 to mim- ic standard 8052 timing, or to fully exploit the high-speed nature of the MSC1210. This SFR allows timers 0, 1, and 2 to be clocked at a rate of 1/12th the crystal frequency (just like an 8052), or to be clocked at the rate of 1/4th the crystal frequency such that the clocks will be incremented once every in- struction cycle. Additionally, the CKCON SFR allows you to modify how long the MSC1210 takes to access external data memory.

MWS (Memory Write Select, Address 8FH): This SFR contains a single bit (bit 0) that enables writing to program flash memory. If this bit is clear, MOVX @DPTR or MOVX @Ri write to data flash memory or data SRAM memory. If this bit is set, MOVX @DPTR or MOVX @Ri write to program flash memory.

TL2/TH2 (Timer 2 Low/High, Addresses CCH/CDH): These two SFRs, taken together, represent timer 2. Their exact behavior depends on how the timer is configured in the T2CON SFR.

RCAP2L/RCAP2H (Timer 2 Capture Low/High, Addresses CAH/CBH):

These two SFRs, taken together, represent the timer 2 capture register. It may be used as a reload value for timer 2, or to capture the value of timer 2 under certain circumstances. The exact purpose and function of these two SFRs de- pends on the configuration of T2CON.

P1 (Port 1, Address 90H, Bit−Addressable): This is input/output port 1. Each bit of this SFR corresponds to one of the pins on the microcontroller. For exam- ple, bit 0 of port 1 is pin P1.0, bit 7 is pin P1.7. Writing a value of 1 to a bit of this SFR will set a high level on the corresponding I/O pin, whereas a value of 0 will bring it to a low level.

EXIF (External Interrupt Flag, Address 91H): This SFR contains the inter- rupt trigger flags for external interrupts 2 through 5. When these bits are set, the corresponding interrupt will be triggered, as long as that interrupt is en- abled.

Special Function Registers (SFRs) 3-7