What was the revenue growth rate for the 8-bit and 32-bit microcontroller products in 2020 
arket. I mean, some of that's in China, it's sold globally. Our 8-bit product line is a 20-plus year product line with a lot of very high quality design. We actually did quite well and grew our -- both our 8-bit and 32-bit microcontroller products in 2020. We think that in 2021 that will moderate -- will probably be flat single-digit type numbers on the MCU side.
And certainly the focus in IoT in terms of the new product development. We are developing a few new 8-bit MCUs to continue to drive differentiation and opportunity in there, but the predominant growth and the focus for the company is on the wireless side. And again those all contained microcontrollers and security and sensor interfaces and all of that stuff, but that's where we're specializing our products, but our microcontroller revenue is going to hold in there solid, and we do continue to invest opportunistically in there where it makes sense, in particular on the 8-bit side. 8-bit still has long life and a very large market opportunity in front of us.
Rajvindra Gill -- Needham & Company -- Analyst
Very good. Thank you.
Operator
Thank you. [Operator Instructions] And the next question comes from Bill Peterson with JP Morgan.
Bill Peterson -- JP Morgan -- Analyst
Yes. Hi, thanks for taking the question, and nice job on the quarterly execution. I was hoping, if you can help us understand within the industrial and automotive or the Infrastructure & Automotive segment, where do you see strength versus weakness, I guess directionally in the first quarter? Should we assume access broadcast consumer down again broadcast auto and the isolation products up and then timing, of course, as well as another impact, especially to margins. Where does that go directly in the first quarter?
John Hollister -- Senior Vice President and Chief Financial Officer
Yes, Bill. This is John, so we expect some of the legacy access products to decline moderating a bit from the fourth quarter that would include the SLICs, which had a strong fourth quarter here. We expect timing to grow in the quarter and also see some continued strength in isolation. So it's consistent with the trends that you would expect for first quarter there.
Bill Peterson -- JP Morgan -- Analyst
Okay, great. And then I guess related to the questions on gross margin. You changed the target model, but I guess a lot of these things we can think about it, at least becoming, I guess better over time, the supply constraints and so forth, especially as we look into next year. So I guess, what's the strategy for changing that now? And should we assume you could get back into the 59% to 61% next year, assuming the supply constraints add from this?
John Hollister -- Senior Vice President and Chief Financial Officer
Yes, Bill, really it's a function of mix, as well as Tyson indicated earlier in the call with IoT and the Wireless IoT coming up, that I mean that mix could change. We saw something additional happened with Huawei or saw timing really take off. But at this at this point given the strength of IoT and how that's affecting the overall mix in addition to the cost situation we talked about earlier that we felt it prudent to go ahead and adjust the model.
Bill Peterson -- JP Morgan -- Analyst
Okay. Thanks for that.
Operator
Thank you. I would now like to turn the call back over to George Lane.
George Lane -- Director of Investor Relations and International Finance
Thank you, Keith [Speech Overlap] this morning. This concludes today's call.
Operator
[Operator Closing Remarks]
Duration: 49 minutes
Call participants:
George Lane -- Director of Investor Relations and International Finance
Tyson Tuttle -- President and Chief Executive Officer
John Hollister -- Senior Vice President and Chief Financial Officer
Gary Mobley -- Wells Fargo Securities -- Analyst
Blayne Curtis -- Barclays -- Analyst
Matt Ramsay -- Cowen & Company -- Analyst
Craig Hettenbach -- Morgan Stanley -- Analyst
Srini Pajjuri -- SMBC Nikko Securities -- Analyst
Tore Svanberg -- Stifel -- Analyst
Rajvindra Gill -- Needham & Company -- Analyst
Bill Peterson --
arket. I mean, some of that's in China, it's sold globally. Our 8-bit product line is a 20-plus year product line with a lot of very high quality design. We actually did quite well and grew our -- both our 8-bit and 32-bit microcontroller products in 2020. We think that in 2021 that will moderate -- will probably be flat single-digit type numbers on the MCU side.
And certainly the focus in IoT in terms of the new product development. We are developing a few new 8-bit MCUs to continue to drive differentiation and opportunity in there, but the predominant growth and the focus for the company is on the wireless side. And again those all contained microcontrollers and security and sensor interfaces and all of that stuff, but that's where we're specializing our products, but our microcontroller revenue is going to hold in there solid, and we do continue to invest opportunistically in there where it makes sense, in particular on the 8-bit side. 8-bit still has long life and a very large market opportunity in front of us.
Rajvindra Gill -- Needham & Company -- Analyst
Very good. Thank you.
Operator
Thank you. [Operator Instructions] And the next question comes from Bill Peterson with JP Morgan.
Bill Peterson -- JP Morgan -- Analyst
Yes. Hi, thanks for taking the question, and nice job on the quarterly execution. I was hoping, if you can help us understand within the industrial and automotive or the Infrastructure & Automotive segment, where do you see strength versus weakness, I guess directionally in the first quarter? Should we assume access broadcast consumer down again broadcast auto and the isolation products up and then timing, of course, as well as another impact, especially to margins. Where does that go directly in the first quarter?
John Hollister -- Senior Vice President and Chief Financial Officer
Yes, Bill. This is John, so we expect some of the legacy access products to decline moderating a bit from the fourth quarter that would include the SLICs, which had a strong fourth quarter here. We expect timing to grow in the quarter and also see some continued strength in isolation. So it's consistent with the trends that you would expect for first quarter there.
Bill Peterson -- JP Morgan -- Analyst
 Okay, great. And then I guess related to the questions on gross margin. You changed the target model, but I guess a lot of these things we can think about it, at least becoming, I guess better over time, the supply constraints and so forth, especially as we look into next year. So I guess, what's the strategy for changing that now? And should we assume you could get back into the 59% to 61% next year, assuming the supply constraints add from this?
John Hollister -- Senior Vice President and Chief Financial Officer
Yes, Bill, really it's a function of mix, as well as Tyson indicated earlier in the call with IoT and the Wireless IoT coming up, that I mean that mix could change. We saw something additional happened with Huawei or saw timing really take off. But at this at this point given the strength of IoT and how that's affecting the overall mix in addition to the cost situation we talked about earlier that we felt it prudent to go ahead and adjust the model.
Bill Peterson -- JP Morgan -- Analyst
Okay. Thanks for that.
Operator
Thank you. I would now like to turn the call back over to George Lane.
George Lane -- Director of Investor Relations and International Finance
Thank you, Keith [Speech Overlap] this morning. This concludes today's call.
Operator
[Operator Closing Remarks]
Duration: 49 minutes
Call participants:
George Lane -- Director of Investor Relations and International Finance
Tyson Tuttle -- President and Chief Executive Officer
John Hollister -- Senior Vice President and Chief Financial Officer
Gary Mobley -- Wells Fargo Securities -- Analyst
Blayne Curtis -- Barclays -- Analyst
Matt Ramsay -- Cowen & Company -- Analyst
Craig Hettenbach -- Morgan Stanley -- Analyst
Srini Pajjuri -- SMBC Nikko Securities -- Analyst
Tore Svanberg -- Stifel -- Analyst
Rajvindra Gill -- Needham & Company -- Analyst
Bill Peterson --