© 2000 Scenix Semiconductor, Inc. All rights reserved. - 12 - www.scenix.com SX48BD/SX52BD/SX52BD75/SX52BD100 Table 3-3.  Mode Register Settings The following code example shows how to program the pullup control registers. First the MODE register is loaded with 1Eh to select write access  to  the  pullup  control  registers  (PLP_A,  PLP_B, and so on). Then the MOV !rx,W instructions are used to specify which port pins are to be connected to the inter- nal pullup resistors. Setting a bit to 1 disconnects the cor- responding   pullup   resistor,   and   clearing   a   bit   to   0 connects the corresponding pullup resistor. MODE Reg. mov !RA,W mov !RB,W mov !RC,W mov !RD,W mov !RE,W 00h Read T1CPL Read T2CPL 01h Read T1CPH Read T2CPH 02h Read T1R2CML Read T2R2CML 03h Read T1R2CMH Read T2R2CMH 04h Read T1R1CML Read T2R1CML 05h Read T1R1CMH Read T2R1CMH 06h Read T1CNTB Read T2CNTB 07h Read T1CNTA Read T2CNTA 08h Exchange CMP_B with W 09h Exchange WKPND_B with W 0Ah Write WKED_B 0Bh Write WKEN_B 0Ch Read ST_B Read ST_C Read ST_D Read ST_E 0Dh Read LVL_A Read LVL_B Read LVL_C Read LVL_D Read LVL_E 0Eh Read PLP_A Read PLP_B Read PLP_C Read PLP_D Read PLP_E 0Fh Read RA Direction  Read RB Direction Read RC Direction  Read RD Direction  Read RE Direction 10h Clear Timer T1 Clear Timer T2 11h 12h Write T1R2CML Write T2R2CML 13h Write T1R2CMH Write T2R2CMH 14h Write T1R1CML Write T2R1CML 15h Write T1R1CMH Write T2R1CMH 16h Write T1CNTB Write T2CNTB 17h Write T1CNTA Write T2CNTA 18h Exchange CMP_B with W 19h Exchange WKPND_B with W 1Ah Write WKED_B 1Bh Write WKEN_B 1Ch Write ST_B Write ST_C Write ST_D Write ST_E 1Dh Write LVL_A Write LVL_B Write LVL_C Write LVL_D Write LVL_E 1Eh Write PLP_A Write PLP_B Write PLP_C Write PLP_D Write PLP_E 1Fh Write RA Direction  Write RB Direction Write RC Direction  Write RD Direction  Write RE Direction mov mov W,#$1E M, W ;MODE=1Eh to write port pullup ;registers mov  W,#$03    ;W = 0000 0011 mov  !RA,W ;disable pullups for A0 and A1 mov  W,#$FF    ;W = 1111 1111 mov  !RB,W ;disable all pullups for B0-B7 mov  W,#$00    ;W = 0000 0000 mov  !RC,W ;enable all pullups for C0-C7